I have a Whirlpool portable dishwasher that works fine with the current faucet connector. The problem is that when not using the dishwasher, the faucet has an undirected water stream that splashes around the sink and the nearby counters.

I bought an inexpensive rubber item in the hardware store that was suppose to simply go over the faucet outlet when not using the dishwasher. However, it doesn't fit without using incredible force to get it over the connector, and so is not suitable for my needs.

Any ideas on other sorts of easy on/easy off connectors that can go on and off over my permanently-in-place dishwasher connector?