Disinfectant is better than nothing I suppose. But the best advice is for anglers, or if you are supplying the keepnets, is to thouroughly dry the keepnets out.
Can't help you with a named product though Michael. Phone your local E.A. office.
Baz is right, disinfectant is better than nothing, but only just. Insisting on dry nets is the only sure way.
Or you could do what an increasing number of fishery owners are doing now and provide nets for your clients for the duration of their stay. Expensive outlay sure, but maybe cheaper if you prevent a disease on your waters.
There is a school of thought that says that net dips cause more problems than they solve. To be successful at all the contents need changing on a very regular basis (every 24 hours some say)and the smell of those dips is very off-putting to say the least.
The one method of killing any infection is to hang your nets up in sunlight for a day, this will kill all bugs 100%. Obviously you cannot guarantee that all anglers will do this hence the need for dips but believe me they need a lot of maintenance to be successful.
Nets need to be dipped for at least 20 minutes to be effective. If you need to look after your stock, how can you insure against a wipe out. I don't think many insurance companies will help therefore I strongly suggest you invest in providing nets and only have these allowed on your fishery. Can you take the risk, 'cause sure as eggs is eggs, some anglers will not give two hoots to any rules or regulations.