Dry skin brushing for athletes?

I have a question on "dry" skin brushing. I'm not sure given my lifestyle when is best time to incorporate this cleansing regimen. I suppose I could do it on awakening, after my glass of water, but my understanding is that one is supposed to shower after. This wouldn't work for me, as I work out in early mornings (if I don't do it first thing of the day, I tend not to do it, so there's zero question of exercising later in day). I usually run or do 75 minutes of prana power yoga (a flow practice in a heated room). Which means I sweat and my skin is not exactly "dry" and even if it were to be dry - if I'm biking home from yoga on a cooler day - it's not clean. Anyway, I guess my question is can I do the dry skin brushing after a vigorous workout during which I've sweated profusely? Should I towel dry first? Is it a problem that my skin is not clean? Is there a risk of pushing the toxins that I've released during the workout back into my skin? One thing I thought of was jumping in the shower for a couple of minutes, towel drying, skin brushing, getting back in shower ... Any athletes here have any thoughts? Thanks in advance ...