Silk screens have some trouble holding up over multiple prints. For propaganda you are probably looking for something stronger than that. I just finished a 3 painting series for the School for the Art Institute of Chicago, which is several layers of acrylic shapes and colors, and than I stenciled and spray painted slogans over them, so the original paintings are pretty hard to see. It came out alot better than I was hoping and seems to be kinda along the lines of what you are looking for, so you might want to try something like that.
These were very helpful- thanks a lot. I like this particular idea of both acrylic and spray paint and stencils.
To get into silkscreening, I'd have to purchase kits and stuff (I do not live anywhere near a setup.) I may put a hold on that for the near future.
Any advice on stenciling while I'm at it?