I made the suggestion only because he was trashing the BB and any tools he bought to work on cup and cone BBs would be worthless to him in the future as he was going catridge. IMHO, it would be better to spend his money on a good crank puller and cartridge tool that will serve him well in the future.

That being said, it can be done without damaging the components. Maybe not in every case but I've not run into a problem even with bikes over 30 years old. Disassembled, cleaned, lubed and resinstalled many in the past without a problem myself (although they were all more or less thrasher bikes to begin with). I wouldn't recommend anyone else go that route if it was a BB they cared about and planned to reuse (of course, if they were sticking with cup and cone, buying the tools would then make sense so it would be a moot point). I'll also add that, as I picked up a pair of new-in-box vintage MTBs recently,I will be investing in the proper tools before it is time to service them.