Typically, in a wet/dry setup the wet amp is a power amp or amp set clean. You wouldn't normally use an effect loop. The dry amp and dry effects generate all the base guitar tone, then it splits off to the wet effects and the wet amp. The dry signal only goes to the dry amp, the wet signal only goes to the wet amp.
For that split, you would typically use Out 5-6 on a PBC/10 or Insert Send on a PBC/6X to go to the dry amp's input. Then any loops after that would contain the wet effects. The main output then goes to the wet amp's input.
What amps are you using? Is all of your gain coming from pedals, or from the amp's preamp?