Do you sit under the dryer on low or medium or do you just air dry.Because I like doing roller sets everyweek or rather than every 2 weeks. but air drying takes so long. cause yesterday I did 4 hour air dyr and 30 mins on mde and last 10 on cool seting is that ok. I mean I want to limit the amount of heat I use. so I just want to know if this is safe.