Zen and the Art of Washing Machine Maintenance

We had one of these annoying small leaks from our washing machine.
It started late this summer, we noticed a small intermittent leak, from somewhere underneath the machine, but it wasn't reliably repeatable, but it was enough to be a concern, not to mention a possible harbinger of future trouble.

We could not find the problem. It is a relatively new and reliable machine, gets used a lot, sometimes multiple loads in a day. So, we called in the pros.

First repairman found nothing, and was rude about it.
Second repairman was much nicer, made several helpful suggestions and left the bill open, expecting to come back...
No, it wasn't that we were using too much detergent.

Problem came back, intermittently. We called the second repairman back and he came and discovered.

Problem was a small amount of "goop" (technical term) on the pump filter, which intermittently blocked it and caused enough backpressure there was some seepage around the seal - enough to leak, but not every time, and not a lot. Yet.

So whence goop?

Well, he said it looked like diaper filler, the new super-absorbent stuff being used by firefighters.
But, the washing machine is firmly post-diaper phase, so whence goop?

Well, the Big Kid had Science Camp this summer. Late summer.
One of the things they made was super-absorbent goop - and they got to bring the surplus home and play with it.
So a little bit of good, about a thimbleful we reckon, got rubbed onto shirtsleeves and pant legs, and from there went into the washing machine.

Most of the time, the stuff was low volume dry residue. So when the machine started up, there was no blockage, nor was there really a problem with normal use.
But, we figure, with heavy use - say more than one or two cycles per day, the goop absorbed enough water to swell to the point where it clogged the filter and started a leak.
Then when we stopped using the washing machine and called a repairman, it dried out and was a non-blocking low volume residue. So no problem when inspected.
Rinse and repeat.

I find this strangely fascinating; in a way reminiscent of the classic "fuel line under the bike seat" sort of way.
Specially now that it is all fixed.