You need to buy good quality German ones. I can recommend the Krupp PenisMeister 2000. They'll never let you down.
something like these come in handy https://www.amazon.co.uk/Pieces-Cau...550694389&sr=1-2&keywords=sealant nozzle caps
Yes I found them when it was first mentioned a couple of days ago. Very useful to know. But it doesn’t stop the stuff in the cartridge from going hard. I’m experimenting at the moment with a cartridge of “Sticks like Sh!t” that I had to open yesterday, and will need again in a couple of weeks. I’m trying the clingfilm under the nozzle method.
I used one recently...had sat for 6 months or so nothing over the end...I just cut 1cm of nozzle off and pulled out a dried silicone slug and was good to go.
Get someone with a lathe to make you up a ‘ everlasting metal’ nozzle. Just need to pull out the old dry silicone every now and again, then.