The clear answer is yes you can use it. But the answer to whether you should use it is probably not because it is messy, smelly and doesn't provide any advantages over just letting the water drain out. It's suitable for sealed systems with radiators but useless for simple open systems like these. There you go. Crystal.
But that's the thing. It's not an open system...it's technically a closed-loop system that, for some odd reason, is being implemented as if it were an open-loop system. I would treat it like the closed-loop system it is meant to be. That type of water-jacket cooling is really best suited to keeping it as a closed loop.
I beg to differ. I consider a closed system to be sealed and pressurised. I see no advantage in leaving fluid in these things when not in use. I have seen some attempts at adding radiators and fans and other unnecessary gadgets to these things and none of them does anything better than the simple bucket of water. All they do is add weight, bulk and complexity. I think that requiring a remote water receptacle is a good idea and actually makes the unit more portable. What would your definition of an open system be?
Every time a YH owner fills a bucket with water (maybe with the addition of ice), and then puts the pump/inlet into that bucket, as well as puts the outlet drain line into that same bucket, they have created a closed-loop system, albeit a temporary one. Nothing new comes in or out of the coolant system for that session, it just exists as it is. That is my definition of a closed-loop system in this context. An example of an open-loop coolant system would be if they hooked the pump/inlet to a direct and continuously running water source such as a faucet, and then let the outlet drain out elsewhere. This open-loop would always provide fresh/new water for cooling, and wouldn't be recycling the same water like the closed-loop system does. Both systems have advantages and disadvantages.
Here's the downside to using an open-loop system such as that: One of the biggest long-term concerns of jacketed cooling systems is the build up of sediment/debris/mineral deposits in the cooling paths. With an open-loop system, you have a never ending supply of sediment/debris/mineral deposits that can and will build up over time. In a closed-loop system those sediments/debris/mineral deposits are finite in number and cannot continue to build up over time.
This is where it gets inefficient with the setup that YH recommends. Because they have users setting up that closed-loop system, but then the users also change the water out each time, they completely negate the positive effects (at least the ones detailed above) of having a closed loop system.
So, in my opinion, users should run the same coolant through the system each time, and treating it with the appropriate type of antifreeze is beneficial.