Besides buski in thymus this is a good quote

"Rhodium is associated with the thymus. When you take rhodium over a period of a month and a half, the thymus grows by 40%."

http://www.syzygyjob.com/smf/index.php?PHPSESSID=1a277eedbd105567e22b0460b054...

You can muscle test the same way you dowse.

In dowsing you want to engage your Pineal\Hypathalamus axis to a vibrating state. This is done via the normal third eye concentration methods.
Be careful here some have powers beyond contacting their guides and can get lost and or invade anothers space...

You want to stay away from remote healing at this point and concentrate on communication with your guides.

To muscle test you can use the identical finger setup as with finger dowsing except that there will be far less resistance.
In short you can finger muscle test by using a very fine touch. Just enough to engage the strength of the opposing finger muscles..
The easiest way to start is to use supplements held against your thymus and muscle test. Best to count how many caps or tabs you need starting at zero...like zero, one, two...if zero is strong you don't need it, else you stop at the first weak number. If one is weak you could use a fractional amount of the supplement...

As for your Thymus it isn't quite clear yet but should be soon...as for Rhodium...it rocks...even better if mixed with m-state irridium and rubidum...