In Germany?

If you hate the cops so much, that's all the more reason to let them deal with the sketchy bombs!

If you call them to pick up dangerous material, in Germany? No. Plus, if you have neighbours, it's not only about you anymore.

All alternatives are a gamble. In many cases letting cops supposedly trained in the matter is the least risky gamble - if they are trained as they are supposed to be there is no risk.

Very few industrial countries where that is a gamble.

Certain DIY things reliably cause questioning or even an investigation by the police despite being legal.

*May depend on race

True. OTOH - I suspect that OD specialist officers, summoned to your property by your "I found something in my garden that looks a lot like that WWII mortar shell in your Call-us-immediately-if-you-see Guide" phone call would be far more benevolently inclined than regular police officers coming to your property for most other reasons.