For chaos it was actually easier for me in milky mode. I bought almost no upgrades/ingredients until I could afford ice and then just coasted from there. The only upgrades I bought were size and tolerance. After a point I was almost constantly milking her but then I unlocked ice and got a few orders with that.in it and just blew right to max size.
I also used a similar strategy for ultra chaos mode, except instead of rushing ice I just got a few of the other "drink" ingredients and basically forced most of the customers to go without milk.