I use this lube on saddles, nut and string retainer on all my guitars and basses.
Especially for the ones who bends often or uses tremolo systems, this will make your tuning a lot more stable than before.
Application is very simple. Provided toothpick is just enough for it. And a tiny amount is usually more than enough. Then just wipe the residue with the provided little cloth.
I have 10 guitars and after using it for longer than a year, the tube is still almost full. That and the improved tuning stability are how I justify the price.
Only cons is that it is a heterogenous solution. So, over time it will release a liquid and you need to shake it a while before using.
Overall, I appreciate Rene Martinez's efforts and he deserves the every penny he makes on this lube! Hope it stays in the market forever.