I'm no authority...but have my personal experiences from refinishing 8-10 walnut stocks with Tru-Oil. I learned that I had better success by using many thin coats as follows:

1) I applied a first thin coat;
2) I hung the stock on a coat hanger in the warm dry house (or a warm dry place) for at least 3-4 days...I basically did a coat every weekend...and if there is any humidity / dampness in the environment it takes longer to dry. Doing stock work in the cold winter time means the house is warm and dry and it always cured best and fastest for me during those times;
3) I VERY lightly slid a pad of 0000 steel wool over the stock surface, and wiped off the dust;
4) I applied a second thin coat;
5) Then I repeated # 2 and #3

Then just keep repeating through this whole cycle 6-8 times or more depending on how much / how thick you want the Tru-oil coat to be. Getting the last coat bone dry before applying the next coat is an absolute must...and an environment of hot dry air worked best and fastest for me.