Chinese medicine is not well understood in western world. This powder may be ground herbs with medicinal qualities such as antibacterial or wound healing however you would need to ask the RN the exact contents.
The other reference I found was to a brown aluminia product. This is an industrial powder but in theory it might have absorbent qualities that may help.
You would need to let the patient know that neither of these approaches are recognized by FDA and therefore we would not know any side effects or whether there was any evidence for effectiveness. That allows the patient to make a decision whether to continue.
However you would also need to check that the products were pure and contained no hidden steroids or aristolochia in particular.
I can appreciate your caution. It is alternative medicine and purity of the powder is not certain.
RE: aristolochia . Would it be toxic if applied to an open wound (not yet fully epithelialized in spots) and the areas of yellow slough present?
She had her treatment yesterday and states that (the yellow slough) became pink beneath (clean healthy bed) and that it elicited no pain.
When the skin is broken then there can be increased absorption from the local tissue into systemic circulation although this depends on many factors. The sloughy nature may reduce absorption initially. I found reports about a local anti-inflammatory effect of aristolochia species however the main discussions about toxicity are based on oral ingestion.
The only thing I can say is that we do not have any evidence about systemic absorption from a topical application so I cannot give any assurances about use. However the wound clearing properties of this powder seem very effective given its short use.