Opportunity is missed by most people because it is dressed in overalls and looks like work. - Thomas Edison
Yes that is one screen two passes. Maybe about 5%water added. Actually it is 60% base or binder and 40% white for softer hand and more subtle look. Sorry just remembered.
Thin the D-White with water for sure. You need not only the discharge itself but enough of the white pigment to penetrate those shirts, if the base gets through but the white pig is floating up top on the fabric they won't wash well. Hopefully you sourced something with a nice, tight weave on the face for this. EDIT: I see you have next level, didn't someone say they won't discharge? Swab test one asap. A poorly discharging shirt would fubar a job like this I think.As far as adding D-Base (clear), that's going to depend on the art and how "white" it needs to be but it will absolutely make the ink easier to pass through yer 305 mesh. We've had great results up to 225 w. 55lpi and D-White, straight up with probably about as much water as activator by weight, so 6%ish, to thin. I like to use the warm water from a teakettle to dissolve the activator and then stir that mixture in at high speed, activating and thinning all at once. Thin too much and your opacity drops as does the print quality with the runny ink but if the white pigment is flusterclucking in the mesh openings then it may actually increase opacity. Got to find that sweet spot for the job.
This print is eight ys old. Black WB plus three colors discharge. 60 line 305 meshPrinted a few thou on this without stencil breakdown or the dreaded "sliming" I keep hearing about