Doug,
Which is why you should leave it to the professionals.
I remember doing an NCCA spotting course with Derek Bolton and because the NCCA wouldn't recommend any proprietary product, he took us through a whole day of using raw chemicals of one description or another and made the whole subject mind bogglingly complicated and spent very little time teaching the practical steps in spot and stain removal, which I thought was a joke.
Suggesting that people, some of whom have very little experience, play around with various chemicals and mix their own is in my view irresponsible and potentially calamitous. There are a whole catalogue of specially developed, tried and tested products on the market today that will remove practically every type of stain from a carpet, so why take unnecessary risks, seems a bit silly to me.
Simon