I have started Master-Cleanse five days ago with coffe ( but without Sugar in it).
I usually drink a lot of coffe ( talking about 5-7 cups a day).
On my first day I had 2 cups.
Next day another 2 cups.
On my third day I couldn't stand the coffe. So, now I dont drink coffe, it makes me feeel better without it.
And trough my five days on MC- I can say that it is not difficult at all, but you need will power and good motivation.I actuually didn't want to give up the coffe,. but it happens naturally :)