How would I wire the switches to be able to turn the pump on OR off from any of the three locations
For two locations, you'd need SPDT switches and wire the same way a household "three way switch" works. For three or more locations, you'd need two such three-way switches and then an additional "four way switch" for each additional location. This is just a DPDT switch that has been wired in an X configuration; Google "four way switch wiring" to see how three- and four-way switches are wired and work together.
You could use a magnetic latching relay. It would still require additional wiring and different switches. I agree, not worth the trouble.