Since They Aren't Front Loaders
Twin tub washers like American top loading units with central beaters aren't bothered by froth. Therefore you can use high sudsing detergents or soaps no problem in theory. However in practice one finds low sudsing "HE" detergents made for front loaders rinse eaiser and faster when using my Hoover TT. There is only so much noise one can stand and time spent with hands in hot water, so the sooner rinsing is over with and faster wash day is done the better.
Easier and faster rinses will be what you'll want if using spin can as the primary means doing that part of washing. Too much froth not only slows down things but can harm the pump and or motor if allowed to go on too long.
Being as all this may however, if you want to use pure soap flakes such as LUX, then all bets are off regarding froth.
No matter how sudsy a soap wash may become, once the rinsing starts is usually starts going away fast.