The Bottleheads swear by them. I think all the parts can be had at the Rat Shack. It's just like a Pi filter but with an identical resistor in both lines. Use RS ceramic .01 1.5kv for the caps and cheap 10R 10W cement resistors (the more inductive the better). The resistors really help the inrush problem too. I built my regulated bench supply this way.Transformer>snubber>diodes>PS filter
--|--VVVV--|--->|---
= = |
--|--VVVV--|--->|--
Just a thought.
Regards,
TC