I described how to feed the cloves in a previous post. For the wormwood or black walnut (I would use the walnut idealy) you need to tube-feed because it is in liquid form and it may be hard to get the tortoise to drink it. You can try, it you think it is ready to drink some water.
If you do need to tubefeed, you need a handfeeding syringe for birds (available at any pet store,) and a lenth of aquarium hose. I'm told dog catheter will work too, but I've never tried it.
To tube feed, you hold the tortoise upright or on it's back and you measure a length of tubing from the top of the plastron to the bottom of the abdominal scute. (The abdomianl scute is the section of large scutes right in the middle of the animal's midsection.) That will make it just long enough to enter the stomach. Then attach the tubing to the syringe. Holding the tortoise in an upright position on your lap (a towell is good in case of accidents,) hold it behind the jaw with your left hand and use your right hand to to pull down on it's lower jaw. It will try to withdraw it's head into it's shell, but your fingers should prevent it from going in all the way. Pull it's head out a little if it goes to far in. After the mouth comes open, GENTLY feed the tube along the roof of the mouth down into the stomach and depress the syringe so that all of the fluid goes into the tortoise. The whole procedure is much easier with 2 people but with practice, 1 can do it easily.
It depends on the size of the animal how much you use of the wormwood or black walnut. For a 3 or 4 inch animal, use about 3 drops in about a quarter-cup of water. 4 or 5 inch tortoise, 3 or 4 drops, etc on up. If the tortoise shows no bad effects, you can increase the dosage by a drop or two when you re-treat in 5 days. I have never seen an adverse reaction, but it is possible I suppose (but it is more likely with Panacur,) so don't overdo it on the first treatment. Sometimes the tortoise will seem a bit lethargic or sickly a few days after treatment. This is because it now has dead critters inside of it that are beginning to rot and putrify. It should expel or absorb them before too long.
If a person doesn't feel comfortable doing this, then they shouldn't try it, but it is really rather easy once you get your feet wet and try it.
I will post a picture in the next day or two showing just how to measure the tubing. Let me know if you have any more questions or if my instructions were lousy.