if you look up cleaning solutions msds and tds sheets you can find the recipes for these things.
this is what most every solvent ink uses as a base chemical
http://www.jetbest.com/download/MSDS/SP+ ink MSDS.pdf
this is basically minus the ink (equals the cleaning solution)
http://www.jetbest.com/download/MSDS/Cleaning Flush MSDS.pdf
(the two main chemicals household names are butyl cellosolve and butyl carbitol the lack of the acetate is not that imporatant. it is the factor for this material to cut ink. the two butyls can not cut ink at all. the are for reducing and leveling lacquers. add acetone and you've got the acetate factor).
here's a good link after a lot of research and reading boring data papers.
http://chemical-news.blogspot.com/2009_01_01_archive.html
currently i just bought a gallon of butyl cellosolve and acetone at sherwin williams. the butyl carbitol evaporates even slower. they are both the same chemical. one an ethylene and the other a diethylene. you can for hours look up the synonyms for the more technical names used in the data sheets or take my word for it. i also for days sank pieces of head adapters, tubes, dampers, wipers, etc in all kinds of solvents to see their reactions. and the result is ketones are safe. if it can cut oil like xylol/xylene, benzene, paint thinner, toluene, then it will destroy the head adapter.
recipe:
80% cellosolve and 20% acetone. and currently the batch i use doesn't have any surfactant. the surfactant is to get under the particles better. because it increases wetting of the substrate or ink lines.
you can mix different strength too for different purposes. if you are wanting to clean off sticky dried ink from you wiper doghouse do a 50/50. if you are wanting to cleaning your capping station for an overnight park use 80/20.
as for the swabs. i have a giant box (thousands) of solvent resistant swabs from the guy i bought my printer from. it's a lifetime supply.
someone could make the argument to just buy it from the ink supplier. but when the material become cheap you will not use it sparingly to clean out lines, do custody washes, etc. and your printer will be better for it.