I think it's a really good option. These would be my tips:
* Make sure parents have access to a LOT of info on MCNs and how good they are for bottoms. My SIL shies right away from them because she is underinformed, and thinks they cause nappy rash.
* Give them an escape hatch like a trial period or something, so that they can opt out if they want to. Explain why you are doing it (use bin space limitations, it's a great point)
* Have one colour for your cloth wipes and another for your face washers, a LDC where I worked did this and it worked really well; no parents ever had an issue with it.
* Have MCNs available for sale - maybe you can convert some folk and expand the cloth empire!!

Good luck!