Cleansing is something one does for oneself but it can be tough specially in a spouse situation when you have them naysaying something that they don't understand in the least or have any interest in understanding. Even if they read stuff they are so set in the middle of the road mentality that they are just not going to "get it" even if it's from the point of view that they just won't admit that they are wrong.
My best advice when dealing with naysayers is to not to talk about what you are doing as little as possible and if they say anything just smile and go about your business. Even a 10 day MC we are talking very minimal results whatever your goal may be so anything less it's just.......well it's better than not doing it at all but you are not getting much accomplished as it takes 7 days +/- for the system to fully adjust to fasting and some actual cleansing to begin. So press on and don't talk about it and walk the walk and let the results speak for themselves.
For me if I'm going to go through all the trouble of fasting and many times the social isolation because many social events revolve around food I consider 21 days my minimum though I generally go for 40 days. It takes 2 weeks +/- for the causative agents to be flushed out and after that is when the actual cleansing at the cellular level begins.