My friend said they took a silk screening class. They used 10xx screen, a wooden frame, varnish, a board as the base and some hinges, staple gun.
Staple the screen to the wooden frame and pull it tight as you use a staple gun to staple it around. It's best to staple directly across from the last staple: (staple at the top, pull the bottom of the screen then staple at the bottom, pull the left side tight and staple, pull the right side and staple) Make sure you staple all the way around the edge and that the screen is pulled really tight. Paint the edges of the screen with varnish (where the staples are, this secures it) make sure not to get any varnish on the printing area.
Nail the hinges to the top of the frame, nail the other half of the hinge to the base board (you may need to add a piece of wood to the baseboard where the hinge will be, this way when you put them together the screen should be flat against the board)
You will need a squeegee and a type of textile paint, my friend doesn't remember what kind so check with the local art store.
For shirts when you are finished you may need to actually cook the shirt in the oven to dry/treat the paint-depends on the paint you are using.
Other useful things, thick paper for stencils, exacto knife, light table or window with sunlight so you can trace, baby food jars for paint.
To get a really good hands on experience check the local college or art studio. My friend says silk screening is so much fun.
Check the answers on this site; http://www.chocophile.com/index.php/crit...
Questions 8-14 deal with screen printing with chocolate. I'm not sure why these chocolate experts believe it's best to screen print a chocolate design onto an acetate film, then transfer it onto the final item, rather than screen printing directly onto the final item. Perhaps it has something to do with working with a rather inflexible silk screen in a frame, the size and shape of the final item, and the possibly curved placement of the chocolate design. It may not be feasible to automate the placement, but manufacturing the acetate transfers should be rather easily accomplished with standard silk screening procedures and methods.
There's lots of screen printing setups for sale on ebay. Making your own silk screens is really interesting and easy, and there's ebay sellers with the emulsion and silk frames.
Sounds like you have a yummy idea!