Hi

I am thinking of getting a portable shower for easy gungings. I'm thinking something along the lines of https://www.amazon.co.uk/Litre-Portable-Pressure-Shower-Camping/dp/B01K6NJ70Y

Does anyone have experience with a similar solution, and/or have any other recommendations?

It's designed for water. I suspect the results will be disappointing as you'll struggle to pump anything thicker than that down the pipe.

I picked up a similar but smaller bit of kit designed for watering hang baskets and the like. It was fine with water, but mess tends to be larger and therefore needs more pressure to force it through and does so with less force - a dribble was the best I could get.