My white paste just came today from Superior Shave also, and I've already applied it to my cotton strop.
I applied it by squeezing out small amounts in different areas and working it into the fabric with the spine of a butter knife. I made no mess, and the entire tube seems to be measured to do one strop perfectly.. i.e. I used the entire tube. If any spots were a bit lacking, i filled those and scraped with the knife like a spatula.
Mine is already alomost dry, and I'll probably strop on it tomorrow.
BTW, I've read that the white Dovo paste has no abrasive qualities, but it sure polished the side of the butter knife!