don't do it!
Truthfully don't know the op or his appititude.
Using diamond paste isn't extremely aggressive.
If he truly wants to learn some skills and without someone at his side, then he has a right to learn if he wants to.
This method of trial and error may give undesired results but isn't that how we all learned to some degree? The worst that can happen is a lesson learned and a part replaced. The op may find he is a natural and has great talent or he may find that this isn't for them. Either way, they followed their passions.
If we tell everyone not to do something they have never done before, then our sport of guns is going to shrink pretty fast.
Evil cannot be reduced thru Legislation!