leather pants drying out need

[Marplot]

I have washed commercial tanned buck skin on gentle cycle with a small amount of Tide. Then lowest heat tumble drying till mostly dry. If they have bead work you may not want to try this. Mine came out clean and soft.
IMG_0279 (2) by Oliver Sudden, on Flickr

Great picture!

 

[andy52]

If you wash them and use a dryer on low heat or fluff and a handful of felt balls they will help soften the leather.
There was a time when I used old sneakers for the same effect.

 

[Johnny Tremain]

Out here in the Pacific North Wet, it may rain a day or two.
The only time folks wear buckskins here is in the dead of summer, when they are way to hot.

My boots on the other hand are tanned elk hide uppers. Gottem in 92 and Ive used mink oil on them since then. They still supple are all these years.

Ive seen some folks fire dry theirs. They seem to crack after that.

 

[Cvkotvkse]

I'm thinking that the "break in" option seems best. Treat them like your making brain tan from scratch.

There was a gentleman on here making very well made propper deerskin breeches, he had a topic on it, but I can't remember his screen name. If I come up with it, I'll post it here and tryptophan draw his attention to your situation.

Edit: it was @andy52 I was trying to think of. I'm curious about his take on the construction of those (something looks off to me regarding the fly, but I'm no expert) and how he would proceed.

Starting over as if breaking out braintan sounds like best option to me. Work the grain side, primarily, as Native-style braintan is sueded on both sides.
Long-departed Seminole friend told me her cousin cut a pine sapling, 2 1/2" to 3" in diameter, off just over waist height; bevelled the end in a somewhat rounded tongue shape, and that was comfortable for her to break out the grain, back and forth over the end. Can do same thing w/ wood (2x4, 4x4, fencepost, etc.) that has been shaped right on end and buried,, or clamped vertically. Have even used a Sears Workmate Bench to do this...

I have no idea what oil, if any. you would want to add to your leathers...

One other suggestion, old bit of advice from Mr. Ayalla of Fugawee Enterprises: If you wet the skin thoroughly, then let it dry enough to be supple, but not as stretchy, and use TWO people to stretch and break it, it goes a LOT more quickly... he told me that he and his son could break out a deerhide sometimes in TEN MINUTES. Never got to see it, but it DID go much faster, and anything else he ever told me was pretty much golden...

Good luck on it!