I cold be wrong, (definitely do your own research on this) but I think bubble hash would be ok still no?
The silver is in the cells of the plant. AFAIK it is not in the trichomes, correct? so the hash would come back clen if it were to be sent away for testing I think?
On that note, what about vaping cannabis? You are boiling off the heads and leaving the plant material behind. Would the silver stay in the plant cells?
I'm not gonna try this personally, but it makes me wonder.
regarding CS, I think making it is far superior to buying it. the bought stuff is usually not the strength it claims to be.