I would use a colander to separate out any loose seeds before blitzing. Maybe even split the pods and remove the seeds. Separating the seeds gives you more control over the heat level. Leaving the seeds in makes pretty much ANY dried chilli powder quite incredibly hot and a little bit bitter if the powder has been sitting around for a while. There’s a chemical reaction much like the reaction that makes english mustard so hot but french and american mustard so much milder.

The plain pods are fine to blitz up - mix with honey and salt for your own sweet chilli sauce that’s a vast improvement on bought muck.