I got an email on this this morning and I'm glad I did as it reminded me that I've been meaning to blog on this.
Pets need spiritual cleansings just like people do. The good news is that they don't need them as often as people do. However, if a pet is sick then I would definitely recommend one and then do them when your intuition tells you that you should.
As far as techniques go, you can use any technique you would use on a person. I prefer a rub down with candles for my pets as it's easier. However, if you prefer you can use the spiritual baths.
After you finish a spiritual cleansing on a pet I would recommend finishing with dressing the collar with protection oil or lightly anointing them with protection sachet powder.