Ditto here Paul.
The Americans recommend a product called, I think, Gloop. Never been able to source it though.
Household silicone type seals are only temporary.
The closest I've got to any reasonable degree of success is with Fernox LSX, you'll find it in the plumbing section of B&Q etc. It's a silicone seal in a toothpaste size tube (yellow box) much better than the other stuff. There is also a black silicone used on caravans which is better too.
I have found that because of the shape and design, a genuine GreenGlide on my Westpac keeps the sealant "protected" better from wet-abrasion wear and tear. So far it's proved to be well sealed for 4 months without problem. My previous glide lost the seal on the edges in less than a week

The other alternative is to attach your wand to a 2" hose. At the other end attach a Boxxer 427. You wont need a sealant then

Safe and happy cleaning

Ken