I picked up a cheapo Lowe's bucket-style shop vac, after seeing a few others try shop vacs in their breweries. It is something like $20
I have a 20g stout tanks MLT, and it is a pain to get in there to scoop out spent grain. The shop vac did it in minutes, barely any grain left at all. Even picked the false bottom clean. That made life easier. I did have to empty the bucket out once, but thats alright.
Then, I kept it by my side for the rest of the cleaning. Getting liquid out of ports, valves, HERMS coil, the residual I couldn't pour from the kettles, various spillages, etc... the thing worked like a champ. I'll be changing from no-chill to a CFC in the future, perhaps, and I think the vac might be the best way to clean it out too.
If you don't have one, I recommend you give it a shot. I got the extended warranty (few bucks more), just in case the brewery burned it out.
One of the best pieces of equipment I've added over the years.