Especially going to people's houses, and working and setting up soft tubs & hot tubs for them.
These are made so you can make them portable, and rent them out to people for the day, weekend or week.
You would come over and set up the portable hot tub, and then come back when they are done with it and pick it back up.
You would set it up for them, and give them a quick demonstration, and tell them to have a great time.
When you come back after the rental time is done, you would empty the water, and take the hot tub away.
You could make up a flier with your prices and rental rates on it, and get them passed out.
A flier works so well for business items like this.
People get a flier, and then tell someone they know, who might want to rent one, or it just might give the person an idea, who just read the flier to think, "hey, I'm going to surprise my wife, and make an enjoyable weekend or anniversary surprise for her.
There are so many reasons why someone would want to rent a hot tub! The object is to build up to having several portable hot tubs at your disposal, and getting some helpers to help set them up for you, when you get to busy to do the jobs yourself! This is kinda like the pool man's job.
Eventually you will be surrounded by girls in bikini's, that want to take a dip in the hot tub! Who could ask for a better part time or full time job than setting up hot tubs!