For a single walking sticks a kettle on a small gas burner will be fine, or a easyier method is a wallpaper steamer and a large pipe like a sewer pipe, block one end of and drop you walking sticks in the opened end, place the nose of the steamer into the pipe and cover it over with a towel.
Expose the walking sticks to the heat for 15 minutes and then very carefully bend it over you leg or knee, keep check the walking sticks untill all the bends are removed, if it doesn't bend put it back into the heat. Then when you have all the bends out of the walking sticks lay them on a flat bench for a couple of hours to let them set.
Its important when using steam to be carefull, steam can let to burns, a pair of gloves will do the trick, a good pair of industial gloves, this is very important when lifting the walking sicks from the pipe when they will be are the maximin temperature, try and not work to close to the heat or steam. Now your ready for the next step with your walking sticks.