Disclaimer
Please note that these herbal remedies given below are NOT to replace any medicines your Vet may give you, but may be used in conjunction with these medicines if you feel they may be of help. Also note that none of these have been properly tested under lab conditions to see whether or not they actually do have a positive effect on rats, so what is said about them is only word of mouth from what people are saying who have tried them.
Use them at your own risk and remember they are not going to be miracle cures, but may help alleviate some of the symptoms only.
After several more months of doing research, most of which hasn't made it to the site as yet, sadly I have come to the conclusion that although a lot of manufacturers make herbals that claim to be a lot of the ones on these pages, the actual ingredients have very little value whatsoever (in fact, some don't even have in them what they claim they are!).
One example is Guarana (not on this site, but still a good example). It's active ingredient actually turns out to be caffeine, so it has all the properties of drinking a few cups of coffee!
Another one, a real disappointment to me, is Lapacho (Pau D'Arco). The main ingredient found in the Lapacho trees (they aren't actually named that, but it is easier to spell!) is Lapachol, which is the ingredient that is supposed to be really effective against cancer. Well, turns out that too much can cause all sorts of really bad side effects, but that doesn't matter much anyway, as most Lapacho tablets don't even contain it! They are basically leftovers, rubbish bits from the trees, unless you can get a really good brand (probably only by prescription). So, they have no medicinal value whatsoever. And I was hoping desperately that they would help our Dommie fight her tumours. Oh well, have to look at other ideas.
So, after all the waffle, a word of warning. If you do want to try any of these herbs, it would probably be best to investigate the manufacturers first, maybe by writing/emailing them to ask exactly what ingredients they put in their herbal medicines. That way, you can be sure you are buying something worthwhile and not wasting your money on a product that probably has all the medicinal value of water.