actually your lymph glands get bogged down quite a bit while you cleanse. they have to filter out the extra load of toxins leaving your system. cleavers is an hearb that helps me a lot, and also with allergies related to lymph and toxins.
it grows naturally like a weed (make sure there's no pesticide spraying if you pick it yourself) but you can also get it in health food stores and it's pretty inexpensive from what i know.
there are also other wonderful herbs for lymphatics that you can take as tea - just google it.
take care!