I had gotten this for cleaning out our woodstove that we use constantly during Wisconsin winters. It's probably a little overkill, but it's great.
ASHJ201 4.8 Gallon 4 Amp Ash Vacuum https://www.amazon.com/dp/B00F3DRDMM/ref=cm_sw_r_apan_glt_fabc_ZFRMY69QC7XNHGDJ3YGX?_encoding=UTF8&psc=1
I got a SnowJoe off Amazon. It was $60 but it’s made specifically for ash. It has a glass cloth pre-filter and a strong motor. It’s a bit pricier than some of the other options but it seems to be made of really high quality parts and worked great.
We got one of these and it works great.
ASHJ201 4.8 Gallon 4 Amp Ash Vacuum https://www.amazon.com/dp/B00F3DRDMM?ref=ppx_pop_mob_ap_share
i’ve got this guy and it’s worked well.