I was looking for something similar, as in a portable club cleaner that would be simple to clamp on a golf cart prior to playing, and easy to remove immediately afterward.
My extensive research from a year ago suggest that no such animals exist.
Funny, but about 20 years ago I submitted a patent for a "shake-clean" portable ball cleaner. It was basically a tennis-ball type round cylinder container, lined with bristle brushes, with a plastic lid enclosure for simple ease of use. Just undo the lid, fill with water and mild soap detergent, insert 2-3 balls, replace plastic lid and shake away!
They loved my idea. Told me they could get me a patent, for $50k investment, and then gave me the details of how they would market it. Kmart, Walmart, etc... I would net approximately 1% of the sale price. So if it sold for 10 bucks, I would make 10 cents for every "shake clean" brand portable ball cleaner sold.
I'm not a math major, but it took all of 20 seconds after reading their offer for me to shitcan their proposal in the trash. Invest $50k to make $10k, tops? No thanks.
With portability being such a really strong selling point for these type of golfing gadgets these days... (can you imagine how much money was made with the sky caddie mount on the cart windshield frame back when they ruled the GPS market and were more popular than laser range finders!!!) or... these magnetic laser mounts for laser range finders on the windshield frames (which I have for my Bushnell V2) that go for $20 bucks...
That V2 laser mount cost all of 3 bucks to make, and my club is selling them for 20 bucks. And I would definitely buy another one tomorrow should I lose the current one I have, because they are extremely convenient and also help prevent me from losing it! Those laser range finders cost $300+! So just for the convenience alone, not to mention as a form of insurance to not lose it? It was a fabulous concept!
Anyway... would love to find a portable club/ball cleaner like what you're looking for, but unfortunately I've found nothing in my extensive searches.