I haven't tried this either, but, yes, Coinery (Stuart) can advise, and I am sure one of his pieces of advice would be to practice on a low value/low grade coin that you don't mind ruining
Yes and they're also trying to influence prices through their grades and auctions which i don't find appealing nor do i find this coin appealing regardless of grade. They're influencing by saying a coin is a certain grade because some people buy by graded holder number. Even IF this coin was £20 i still would'nt be interested, just my opinion