Snake Oil isn't what I'd consider "Green"... It is however safe & very effective. The 2 main ingredients that keep it from being "Green" are butyl & amonia. That said,
www.EncapStore.com sells several green products including Vacaway EncapGreen & Intensity Green,
Releasit Bio Encap & a few others...
At any rate, assuming the chemistry is equal in enviromental impact I think VLM is generally more friendly to the enviroment on the whole. Less fossil fuels, less water used (even after washing pads), less of that water makes it directly to the rivers streams and oceans... Of course with the use of the Green Cleaning Products the enviromental impact is again reduced but I can't say to what degree...
I will say that people should be careful with green & all natural products as green doesn't always mean safe & good for the enviroment. Rattlesnake Venom for instance is 100% natural, some plant based products could require trees to be cut down to make room for the new crops to be planted, or the plants have to be transported great distances increasing the carbon foot print, etc. Honestly, I think the greenest product is the one that prevents the carpet from being replaced...