My family has always used feather blankets called a "pierzyna" (which I can't describe how to pronounce very well) it's a lot like a german feather bed though only it's a blanket to have over instead of something you lay on top of… anyway, we just wash them with some gentle soap, with some extra borax added, no idea why, but that's what my grandmother said to do!  Then we hung it over the line (over/across two lines that are side by side works best, but it's not necessary) to dry most of the way in the sun then in a dryer with a clean shoe which will fluff the feathers.

These are unbelievably warm, too warm actually, but back when the attic wasn't heated, it was a very welcome thing!  (ask me how I know!)

Anyway… point is, washing and drying is actually the best thing, it's perfectly safe, and to wash before stuffing in the thing you are making, just put them in a sack of some sort that either ties up really well or actually sew them in an old pillow case… pack them loosely for the washing and drying, don't forget that they'll fluff up a LOT in the drying, so don't pack them much even if it means doing it in several batches. 

I have done this with old feather pillows, torn them open and gathering the better feathers from them, leaving the 'dust' and feathers which have broken down, then combining two pillows into one. Make sure you're in a closed up room, spread a sheet on the bed and don't let anyone open a window or turn on any fans.  I always wash them before repacking the 'new' pillow.

My mom said they used to make the pierzynas from scratch, Grandma used to save feathers from the chickens and ducks they butchered, and then they'd 'tear' the downy parts off the shaft and even use some of the harder parts too, if they were nice enough.

Hope that helps!

They still make ticking, in stripes of all colors which is traditional, but also in flowers and other patterns too which is what my mom got last time she redid our pillows not long before she died.  I suppose it's past time for me to look over all our feather pillows again.

It's not so much that it's heavy, just woven very tight.  There also is a solid colored fabric that is still woven very tight but much lighter.  it's better for things like duvets (what we Poles call pierzynas), feather beds too.  I think for some reason they call that featherproof or downproof ticking which I found out when I went looking for the fabric just now on line.