Personally i like settling in the sump because those big particles have to settle somewhere and I'd rather them settle there.
Basically my contraption is similar to what @mcarrol is describing. The plastic pvc fitting fits exactly on my vacuums hose. The hole on the top is the opening for my thumb. I have found that if i leave it completely open it has good suction and fairly low flow rate allows for good cleaning with minimal water removal.
Very nice! Thank you for sharing. I think I'll give both ideas a try and see what works best for me. Do you know off the top of your head by chance the size/diameter of the tee fitting you used (I'm assuming that your shop vac and mine are the same size) and the size of the tubing you used? Again thanks for the help!