Not mad at all but there are some difficulties in regulating the temperature you need to be aware of. In a washing machine there is a closed environment so setting the temperature is fairly easy to do. Controlling the amount of heat from the element is tricky so rather than control how much heat, a washing machine will simply turn it on at full power then turn it off again periodically, repeating every few seconds. The shorter the 'on' bursts, the lower the overall temperature will be and the longer the bursts hotter it will be. Some controllers use the thermostat (it is actually a resistor that changes value with temperature) to decide how long the bursts should be, some just do it on a timer and hope for the best!
In an open environment like you propose, there are several options, none of them ideal but all do-able. Your heat demand is likely to change according to what you are washing because of the ambient temperature the liquid is passing through and because some of the parts will cool the liquid down due to their own thermal needs. Just turning the power on in timed bursts is unlikely to be successful because there is no feedback to cater for the changing heat loss. You could adjust it manually by altering the timing yourself but that might be tedious, especially if up to your elbows in chain grease. It is possible to use the thermostat to sense the temperature, compare it with a pre-set figure of your choice and use that to turn the power on and off.
The more technical solution is to use what we call "phase control", essentially like a light dimmer but with the heater instead of the lamp and the thermostat instead of the brightness control. It gives continuous regulation of the power passed to the heater to maintain a fixed liquid temperature. It doesn't completely turn the power on and off as such, it chops each AC mains cycle to make it longer or shorter. This method gives finer control but you would have to build some electronics to make it work.
Brian.