Yeah, clean up crews are overrated...I think that stores and websites just make a ton of money off of things like reef "tune-up" crews and push them on people.
I have a couple of turbos, some narcarious (spelling...I know...too lazy and intoxicated after an archaeology conference party to look it up), and about a million collonistas, and I think the collonistas do more than the "real" cleaner-uppers combined. I have three or four hermits, and I guess they do stuff...I think that most of my clean-up comes from Those Things Which We Do Not Normally See; the hitch-hikers that come out at night, pods, and so forth. This is in a 25, by the way. My wife's 40 actually has FEWER purchased clean up critters and is probably "cleaner" than the 25.
So yeah hibye...go easy on the snails, I'd say. No need to overdo it. "Nature" will do its thing if you steward it well.