Manson's vocal chain was a Telefunken 251- Neve 1073- 1176 LN- GML 8200. After that, he did all the work. As far as mix, I think Tom had his usual vocal chain- I doubt it was very involved.
For Flea- on "The Uplift" record, he went DI without any amps. For "Mother's Milk", he had this horrible Mesa 400 (?) power amp/preamp system which we split with a DI- pretty sure we favored the DI. I seem to recall he used a Musicman.