Reddit mentions of Grodan A-OK 1"x1" Sheet of 200 Rockwool / Stonewool Starter Cubes for Cuttings, Cloning, Plant Propagation, and Seed Starting

It is mathematically not worth your time. Say it takes 1 minute to clean it in hydrogen peroxide, (it doesn't) and there's no mold, algae, etc. 1 minute @ minimum wage US = 12 cents.

https://www.amazon.com/Grodan-Rockwool-Stonewool-Cuttings-Propagation/dp/B0087SJ3U0

200 cubes for ~$16 = 8 cents.

It's cheaper, easier, and better just to throw them away, or you could switch to aeroponics and not have to worry about it :)

There are products like a starter plugs you plant into these once you get roots it all goes into a hydro system.
https://www.amazon.com/General-Hydroponics-Rapid-Rooter-Replacement/dp/B0002IU8K2

You can also use rockrool and grodan and seed directly into the cubes or whatever you choose. I would shy away from starting soil and moving over.
https://www.amazon.com/Grodan-Rockwool-Stonewool-Cuttings-Propagation/dp/B0087SJ3U0

They're pretty good for starting. The pellets readily wick up water, but they dry out quickly and thoroughly. As long as they're under a humidity dome, they're fine, but after you uncover them, transplant soon to avoid moisture issues -- either with algae due to too much water or stunting/death due to too little water.

When you transplant, be sure to cut off the netting. Some brands of pellets have netting that tears away easily than others, but I find I'm not really willing to deal with rootbound plants or unsightly netting in my soil. I always remove the netting and toss them in the trash.

I just picked up some mineral wool starters. I've heard good things about this stuff. I have a 72 cell tray that I'm starting some reapers in -- some cells with the mineral wool cubes and others with premixed garden soil. I'm curious to see how they compare.

Edit: I just realized you're not starting in the peat pellets. If you're not germinating with the peat pellets (which is what I do), then I'd probably just go straight for a 72-cell tray and mix your own soil.

Go the easier route http://www.amazon.com/gp/aw/d/B0087SJ3U0/ref=mp_s_a_1_3?qid=1464730950&sr=8-3&pi=SY200_QL40&keywords=grodan+rockwool+cubes&dpPl=1&dpID=51nlxtWAe4L&ref=plSrch or http://www.amazon.com/gp/aw/d/B0002IU8K2/ref=mp_s_a_1_1?qid=1464731037&sr=8-1&pi=SY200_QL40&keywords=seed+starter+plugs.way higher sucsess rate and never get root bound.