Having done a fair bit of plumbing, I can assure you with 100% confidence that turds float just as well as cream does.
touche........in this instance some turds are supported (by airheads), but their identification is usually obvious to another plumber and/or someone that's been familiarized with plumbing.
if identification of the turds were introduced to the general population the plumbers likely to be a real busy guy.
as long as they would agree to express your limitations and expectations of the product, i can't see any down side to expanding your market.