I would say yes.

Hi, welcome to GoY, yes you can, it won't do any good, but it won't do any harm either, it will get rid of the ash for you, as it washes into the soil, but it will do nothing for the fertility of the soil, or anything else, Derek.

I do it all the time - yes you can.

Personally I wouldn't if it is just burnt papers... Wood ash yes but even the Bulba adds to potting compost rather than onto the soil. In my view better to recycle the paper.

Paper ash ON the garden would be of no use since it will quickly blow away. On the other hand paper ash IN the garden is good so be sure to turn it into the soil as you lay it down.