My 'steam treatment' is in the shower. I use very warm water to rinse hair then I apply conditioner. I put the cap on and let very warm water run over it for several minutes then keep the cap on while doing other shower stuff. Remove cap and rinse. I don't recall where I found that suggestion but it works great for me!!
remember, with all advice or suggestions for your hair, YMMV!!
My hair:
2b wavy, medium texture, low porosity, med-high density. Protein finicky.
My routine:
Cleansing: DCNP, every 4-5 days (occasionally use CJ cleansers).
RO: CJSC, occasionally use JCDC
Gel: KCCC, CJCIAB for 2nd day hair (sometimes third)

Heat is my friend: warm water rinses, steam caps, and diffuse dry. I love CLU cloths and my Denman.