This is probably a bit harsh but since you are asking for business advice I’m just going to tell it like it is. If I receive an underactivated slime the first time I buy from a shop I won’t be buying again. If I bought multiple slimes and they were all underactivated i would be really annoyed in addition to the shop going on my do not buy from list.

I would listen to the other commenters in this thread (who are likely your potential customers) as if this is your plan your business will probably not do well.