Who has a swamp cooler that's small enough to use with "eggs." If you could post some pictures I would really appreciate it. Also, how's the power consumption?
When I bought my Fiber Stream
it had a Coleman RV Evaporative cooler.
When I first saw it, I thought it was an Air Conditioner. It had too many water issues for me, and I replaced it with a Fantastic-Fan.
These hoses are how you added water. One is a supply, and one is an overflow drain. You had to connect the supply hose to a garden hose, and fill the roof-top tank until it ran out of the overflow. Then you connected the two hoses together and left them dangling from the side of the trailer. The cooler worked until all of the tank's water evaporated, then you had to refill it.
It was highly prone to leaking and was very messy.