Last one I did, I created a trough wide and deep enough to cover the stock, followed the instructions on the package, and poured it over the stock. You'll need something to hold it under, since it will want to float.

The trough was heavy cardboard, the liner a $2 shower curtain liner.

 

I started using RIT dye years ago, back in the early 80's. That was the only way I could find to get a good color in the crappy old birch stocks of the day, which back then all I used was the brown dye. The way I use to use the powder was to put it in a quart Mason jar and fill the jar with denatured alcohol, and I would keep it in the shop to use as stain. Using the alcohol it takes some time and effort to get it mixed, over a few days you have to keep mixing it or shaking it up and let it set to settle. Then before using it you need to run it through some cheese cloth or a paint fillter. It was a continuious process for me to keep some good brown stain in the shop.

Luckily I have found an easier way that works for me with the powder. I'll take a couple cups of water and the powder, put it in an old pot and boil it on the stove until its reduced down to about a cup, take it off the heat and let it cool. Put it in a jar and add a 16oz bottle of alcohol to it.

Some people prefer to use all water to cut the dye, and thats fine and works great. Myself, I use it like a stain, I dont put it on the stock until all the sanding is done and ready for finish. By mixing it with the alcohol it doesnt raise the grain like it does with pure water. And to me it just seems to penatrate deeper into the hard grain of the wood with the alcohol.