Sculpters: getting oil based clay to stick to latex?

Hey all.

Situation:
I have a partially covering torso+head latex appliance that I have removed the face from with the intent of sculpting a new one so that it better suits my oen face. (I am going to superglue the new face to the old appliance with some overlap after casting.) I have the appliance over my complete life cast (head and shoulders). The idea is to sculpt a new FACE over my life mask and marry it seamlessly to the existing latex appliance. However, I am finding it difficult to get the oil based clay to stick to the latex, making covering the seam a bit hard. I've tried diluting a bit with isopropanol but that didn't really work. Mineral spirits seems to work a little better but I thought I'd check if anyone had any better ideas.

I know Vaseline works for super sculpey, maybe it would work here as well, just rub it on and wipe it off. The petroleum in the vaseline may hold the clay. worth a shot.

I think the mineral spirits are working since they also dissolve the latex a bit but maybe I'll see if the petroleum jelly works.