I generally DC my hair BEFORE I wash. I put my DC on dry hair, leave it in as long as I want to, then finger detangle, rinse, cowash or shampoo, and then comb through my rinse-out conditioner. I do use loads of conditioner, but it works for me.
OP, I spend half my time in west africa and have to deal with the humidity shrinkage issues you mentioned, so I am going to try out this method and see how it works for me.
Products in current rotation:
Terressentials Pure Earth Mud Wash; Elucence MBC (now really just for cowashing, leg shaving or emergencies); Curl Junkie: Repair Me, Deep Fix, Curl Rehab; AOHSR (retiring); Oyin Handmade: Honey Hemp, Hair Dew, J&B; Qhemet Biologics: BRBC (retiring- prefer Oyin HD), AOHC, OHHB; Jojoba Oil for scalp; Castor Oil or Shea butter to seal; Henna & Ayurvedic pastes when I can be bothered.
Still searching for the perfect stylers, but loving CJ CIAB over everything so far