any reason for the string vs. the rubber bands? you might find it difficult to get the string tight enough to hold the comb in the way you want. the bees will remove the rubber bands in short order...or build around them :-D
i usually put 4 fat ones on each frame before i start. makes it easier to slide them over and hold the brood. your fingers will be sticky and if you are wearing gloves (as i do) you'll have heavy, sticky, fingers. the less you need to do, the easier.
also allow at least 3 hours and since it's your first, maybe more. it will depend on what you find when you get in there.
spend some time in the removal forum reading about how to remove comb, where to start, and what you will need. you have some advantage being at home, but you don't want it to be any more frustrating that it has to be!