Absorption.
There's a reason that alcohol tinctures are so popular.
That reason being, alcohol + water absorbs most of the actives that we want out of a plant.
Your usual tincture is made either from fresh herb + 95 % alcohol; there, the water is in the plant. Or it's made from dried herb + 50-60 % alcohol; there, the water is in the liquid.
Either way, you get both alcohol- and watersoluble constituents out of the herb. (British tinctures are far weaker in alcohol, though.)
Here's a handy list for what constituents are pulled out into what kinds of liquids:
Alcohol: everything except minerals and trace elements. Mucilage is absorbed but is then split into simple carbs - so there's no mucilaginous action. Unless you do British-strength tinctures, which means very little alcohol to a lot of water.
Water: everything except resins.
Vinegar: minerals, trace elements, alkaloids
Glycerites: some minerals and trace elements, some alkaloids, some acids, some mucilage
Oil: oils, resins.
Syrup: oils, resins, sugars, mucilage.
If you have problems with alcohol you should substitute teas for your tinctures. They're not as handy (as in, you can't just take a cuppa while waiting for your bus), but you can always make a batch in the morning and carry a bottle of herbal tea with you.
You can also eat the plants as is; it's not all that practical for flowers and leaf, but it's easy to keep a tiny jar of dried root bits with you and just chew on a piece now and then.
Glycerites are nice and all that, but they're not even half as good as real live alcohol tinctures.
King's Dispensatory lists 6 vinegars, 12 glycerites, 29 powders, 34 infusions and decoctions, 52 syrups, and 97 tinctures (not counting the extracts).
I'm sure I've forgotten one or the other menstruum (= liquid) and one or the other set of constituents pulled out into the ones I've listed. Feel free to add your comments.
Darcey: vinegar, check. Easy
Darcey: vinegar, check. Easy to overlook, I grant you...
Alex: I think of Epilobium as a tea herb, but then, I find the taste of glycerites disgusting.
Dunno, the ones I've seen
Dunno, the ones I've seen all have a hole at the top, which makes them less than useful for a "on the bus" scenario. As in, all your stuff covered in, say, coffee, or tea, or whatever.