They might as well just stack taxpayers money into a huge pile and throw a lit match on it.
From a basic economics point of view, setting light to the cash would be better.
When you burn cash you remove it from circulation, which makes the rest of the cash left in the system all worth a bit more. Alternatively the government can print (and keep) the same amount of money as you burned - net result, a transfer of money from you to the government. Result: burning money is the same as paying it to the government (just as if you had paid extra tax.)
In contrast, when you spend money, it stays in circulation, and the government doesn't benefit,.
So, in this case, stacking money in a big pile and setting light to it would be a more productive use of it.