help with clay sculpture

Hello everyone, I recently finished sculpting melvin. the 1st project assigned to introduce me to sculpting. but i've come across an issue..I'm trying to smooth out my sculpture with 91% rubbing alcohol but it leaves behind a white residue. so i try going over it once more with more rubbing alcohol the white residue still manages to reappear once the alcohol dries. is there a solution to this?? cause i'm getting kinda frustrated.lol