You could pull a Goldfinger, and irradiate a bunch of gold bars, or otherwise render your wealth unvaluable or unspendable, but that just decreases the wealth supply and makes everything else in the economy a tiny fraction more valuable.

Even if you bought an extravagant Viking funeral, and burned your grave ship, and sank all your treasure to the bottom of the ocean, the world still turns without you. The value of money, goods, and services still depend mostly on the active participants in the economy. When you destroyed the representational tokens for the wealth in the economy that you controlled, their value was immediately redistributed to all the other tokens in existence, and those with the information about the destroyed tokens can theoretically earn arbitrage profit by spreading that information around.

The best you can do is to write a program that spends your estate after your death, give it to your lawyer to compile and execute on the legal mainframe, and hope no one can hack it before it accomplishes your intended goal.

This is way cooler than my gold coffin idea!

Finally, a use for Etherium I can get behind.