And still do… Have used it on my guitars, bass’s and banjo’s for over 50 years… I’ve also used “Panther Piss” (Penetrating Oil - The “real” stuff - NOT WD-40) every once in awhile too…
Hell, use what ever works for you just as long as it can’t also be used as a pie filling, cake topping, meat marinade, cocktail mixer, smoked in a vape pipe, or used as a substitute for K-Y jelly!!
Keep on Thumpin’!
Lanny
Great thread! @eric.kiser Thanks for compiling this info down to your post. I actually really needed this right at this moment because I ordered myself the PRS 3 cleaning, conditioner & polish bottles that just came in today.
I got small guitar tech kit too but realized later I changed on of my orders up because it was out of stock so I forgot I was out a brush for scrubbing the frets when they arrived today. I know some just use soft steel wool for that though.
I really like this stuff on the frets, much more than steel wool (no errant steel fibers looking for magnets). A small square is all you need and one package lasts a long long time.
https://www.amazon.com/Gorgomyte-Fingerboard-Cleaning-Original-Version/dp/B00A9K386E
Thanks for linking that, the kit came with 3 cloths for each step but I figured if most use steel wool then I needed something more abrasive than those cloths to scrub those frets clean.
OOPs! 
I’ve always used
Old English Furniture oil on my rosewood boards
Yeah not sure what is in the cloth, but it works wonders…the pale white cloth is pure black when you are done.
Use a furniture oil here.
I’ve got 2 bottles of the Dunlop lemon oil but after reading @terb comment regarding it being more of a cleanser than a nourishing product I’ve had second thoughts about it
Cleaned my bass and guitar. Guess what? You were right! I didn’t really need that soft wool after all, the included cloth was more than enough. 
Not only is it clean as new, it sounds brand new & it smells nice.
These D’addario NYXL bass strings I put on them sound 800 times better than my last set of roundwounds. So bright, clank comes natural with them. In love with this pair of strings.
I love D’Addarios. I use the normal nickel rounds but the NYXL’s look awesome too. Definitlely my string brand though.
Me too, I actually bough several packs of strings and put about 4 of those player circle codes this week when my strings arrived so I used my accumulated points to order me a free set of strings which will come later this week.
Can’t believe that to be honest, I think I bought 4 packs of strings from them which made my 5th pack free. I have a new addiction with that players circle system. 
The other day I damaged my palisander fretboard with tiny scratches when I was replacing my strings and cleaning my frets. It wasn’t my fault tho, the fretboard “guard” apparently had sharp edges 
Was hoping the oil would fix the scratches on the fretboard but it did not. After some research I decided to sand my fretboard with very high grit. Let’s just say I was surprised how much dirt was still on the board… It looks fine now but I was pissed about buying something that should protect the fretboard and not damage it. I also sanded the edges of the fret guard. Not so sure if I’m gonna use it ever again or just use tape… Hopefully you won’t make the same mistake.
OMG what a disaster, I had a sunken stomach feeling reading this. I’m sorry to hear that. I’m nervous about my new fretboard guards that came in last week now.
I hope you’re able to take care of this issue! Please let us know how you accomplished it also.
What do you clean your frets with?
I have the Music Nomad ones and am also nervous about them and thought to buff the edges before I use them
Sorry to hear about this @Paul
Those things are usually just stamped out in multiple lots and are prone to having sharp edges at least mine did. Fortunately I checked before hand and cleaned up the edges.
My radius gauges and string height guages had the same issue, probably for the same reason.
I have used good old masking tape above and below each fret before rubbing the stains off last time around. Then I remove them and move to the next fret. I guess it is slightly more work to use than that metal piece but after reading your message I am happy that I did it this way!
Well I solved it with micro mesh pads. You can use them for simple precise application for intermediate cuts, polishes and paint corrections. Started with 8000 but that only took away dirt. Think it was 2400 or 4000 that finally made a difference.
I usually clean my frets with a cloth but these frets were really dirty. I just used a polishing rubber what did worked well with the guard.
Anyway I learned my lesson…
Good idea, I’m going to do this either way now. What do you think is suitable to buff the edges down smoothly without adding even more abrasive scratches on the fretguard?
Thanks for the quick shout & sharing a terrible experience with us so we could be reminded to not make such an easily made mistake ourselves as well.
I’ve saved all your links. Made me realize I forgot to buy fretboard erasers last week. Going to buy mesh pads too because I only have those micro cloths.
I also have the music nomad ones, just used the fret polish kit for the first time. my thoughts: I had no problem with the guard scratching but nonetheless I think masking tape is a great idea and the way to go here. the product worked fine on my darker fretboards, but on maple fretboards left ugly dark residue on the wood. luckily I also had the F-one fretboard cleaner which cleaned it right up. and finally, I just really didn’t need to use this. unless your frets are in horrible shape, I’m guessing maybe doing this once every couple of years would be plenty.