Tek used something called Kellite in their wash station. Tekwiki has an article about it in it's maintenance section under "cleaning", and I think there are threads on TekScopes as well. Kellite, seems to be no longer available, and I've not found much information about it, except that it may have been a buffered phosphate type cleaner (no chemist here, so be kind!). I remembered using Alconox in a couple of chem classes for cleanup, and it is phosphate based as well. I've used it to clean two 500 series plugins and a 575 at this point and it worked very well, and doesn't seem as harsh as straight TSP but that is a subjective evaluation (TSP absolutely lights my hands up, the Alconox didn't). I use the same type of siphon gun as Tek, and follow up the Alconox with DI water, and then IPA through the siphon gun. I think the same cautions Ed recommends with respect to it being potentially corrosive to aluminum if not thoroughly rinsed are appropriate. Initial cost of a four pound carton is a bit steep, but it will last you forever.

Tom