Methadone and Herbals/Ethnos?

[baron samedi]

SWIM is unsure as to whether this thread should be in the main Opiate section or the Ethnobotanicals section instead of this one but anyway.
SWIM has been trying to find information regarding potentiation of methadone without a great deal of success. He has been drinking Grapefruit Juice beforehand, but whether its made a marked difference is hard to gauge. He's unsure if he should be drinking before or after meth consumption or what. He's heard that stomach meds might work but does not know how true this is. Obviously, he knows that benzos/weed/alcohol would probably work but has not tried any of these methods yet (except benzos for sleep purposes).
Anyway, sorry for getting away from the topic about which he started the thread, but he's wondering if any fellow methadone user's, past or present, or people with knowledge of the drug would recommend combining it with any herbals/ethnos, as an alternative to the benzos/weed/alcohol method, or simply for the sake of using a particular herb or plant? He is not really interested in anything hallucanegenic, as this is not SWIM's cup of tea. Apart from that anything goes for SWIM, providing he will live to see another day after taking them. Really, he's looking for something to synergise well with the meth, providing some additional relaxation or euphoria. He has plenty of relaxants (kratom, kava, mulungu, skullcap, blue lotus etc) at his disposal. He also has stimulants such as ephedra and non-herbals like bzp. Whether a stimulant would go well with a drug like meth, he is unsure of. He also has quite a bit of (probably stale by now) spice and other smoking blends. There is something about the spice after-effects that SWIM really doesn't enjoy, making him feel weird for several hours afterwards, so he's hesitant to try it with meth. Are there any other smoking blends, which work but don't have as bad side-effects, that he could use with meth?
Sorry if this thread is a bit wide-ranging, but he would be interested to hear other peoples experiences of using herbals/legals while on methadone, or peoples views on such a combination.
Cheers