I don't think is working in this way. It must be a server data file so the removing of cookies should not works. Can someone confirm if it works?

If you don't have an hardware wallet you can use Exodus a software wallet a lot of supported cryptocurrencies, it also started the support to erc tokens.

Seems we can but only for few of them! Nice to know!

Do not share private Keys.
Save your Keys in a different devices or papers and store them cutted in half on different locations.
Save webiste if web wallet on bookmarks.

Wow people are doing everything to stealing from others.