I never knew there was any law against using rooting hormone, or selling cuttings that had been dipped in it.
It seems like an unenforceable law after the first few weeks or months. Root it, wash the soil and remaining powder off, repot it.
I thought the law prohibited asexual propagation of certain "patented" plants, usually tagged "propagation prohibited". If the plant variety is tagged "PP", I think it is unlawful to propagate it asexually (cuttings) with or without hormones, for sale or your own private use.
I always wondered what "they" would do to a PP plant that reproduced itself asexually by runners: fine it? Lock it up in a smaller pot for 5-10 years?