Money varies quite a bit depending on the going rate for colonics in your geographical area and whether you set up your own practice.... work as an independent consultant in someone else's business... or if you are a salaried employee. Likewise... there is considerable variability in the number of clients you can attract... based on some of the same factors... as well as your ability to network, how skilled you are, and how comfortable you are in working very closely with people. I would suggest that you contact other colon hydrotherapists in your area and pose your questions to them. Some will be very helpful and you might also get some leads on possible future employment opportunities. Most of these positions are obtained by word of mouth and... as in any other field... getting a job largely depends on who you know.
This link should help... in case you don't already have it...
Also... be aware that this is a much tougher line of work for men. As a rule... both women and men feel more comfortable with a female colon hydrotherapist and you should carefully consider that when making your decision. The male colon hydrotherapists that I have known have best addressed this by targeting a niche market and also obtaining additional training in some sort of body &/or energy work so that they can offer additional services.