question about hot rollers

Hi, I am committed to growing out my hair strong and haven't been using curling irons, hot brushes, blowdryers, basically heat of any kind. I have heat rollers that are covered in sponge material with no sharp teeth or anything like that. If I condition regularly and am very careful, do you think I could use them once in a while without too much ill effects? (It usually takes about 20 minutes to set my hair.) my hair is f/m but is usually pretty strong. it is virgin hair. It is just below my chin in front, slightly longer in back, and I am trying to find ways to create volume since the blow dryer is out.

Thanks,

Wendy