Whilst working as a gardener last summer the other Gardener would often rub a cream into their hands before working which prtected their hands and made them water resistant.
I am now working as a pot washer and want to get some.
A good barrier cream is Diprobase which you can buy at the chemist ....but if you are doing huge amounts of washing up it would be cheaper to invest in some rubber gloves :)
The detergents in the washing up liquid will soon render the barrier cream useless on its own as well as removing the natural oils that are on your hands - do use it but wear protective gloves as well.
If you are alllergic to rubber there are vinyl washing up gloves available as well and use a good moisturiser ( I use Neutrogena ) after work as well.
as said barrier cream washes off.
try rubber gloves and get a couple of pairs of thin cotton linning gloves so when one pair gets sweaty you can stick another pair in and dry the first.