To be safe, I would say yes. Mainly because silkies do not have the 'waterproof/water repellent' feathers like most chickens. I don't know how well it would dry even though that sounds like a comfy temp (for me at least ) or if it would be too chilly
I have one that I cannot blow dry. I give it a bath and towel it off well and put it in a bin under heat lamp until it is dry. I have no clue how long it takes. I just check her/him every couple of hours til it feels and looks dry.
IDK about using mane & Tail. I use that for me & the horses...