I don't know. The only homoeopathic remedies I know are the tiny pills, with no alcohol (?) Just sometimes lactose sweetener.
But I have limited experience with them, and no experience with "mother tinctures" (is that what you mean?)
But for herbal tinctures made with alcohol, I have heard that putting the tincture into freshly boiled water evaporates the alcohol but leaves the herbal properties intact.
But I have never had cause to do that and don't know how 100% effective that method is, and how thoroughly tested it is. It could be very important if no amount of alcohol at all must be taken (regarding interactions with certain drugs etc)
Also with herbal tinctures it is sometimes possible to obtain them made with glycerin and even with apple cider vinegar, though those don't store well for a long time.