I would just set up the tub and put her there after the fw dip . Do not forget if it’s your first time freshwater dipping a fish u must match the ph and temp to ur display tanks ph and temp or your fish may die, I’ve messed up two freshwater baths so far and killed two fish. Maybe others can answer a little bit more than I can but basically you need to do whatever you can to get that medicine freshwater dips will only get you so far. and you need to treat all ur tank inhabitants for this disease also, it’s not clownfish specific/host specific