Sometimes ignoring undesired behavior does work, but you must be consistent.
He very may well be doing it for attention. What can really help, is "catching" your son being good. Pay attention to the littlest of things, and when he does something right or good (even if its something small, like throwing away his trash, or clearing his spot), say something like, "hey, that's great you're cleaning up after yourself, I like that".
If you see he catches himself and doesn't swear when he typically would, you can say, "I noticed you were going to say something - a swear word, good for you for using self control" Praise him up and down......that is another form of attention, just uplifting for him.
After a few days, if you notice your son is now really trying to please you, you could say, "I have been noticing how great you are doing at controlling your swearing and helping out around the house, let's go for ice cream on Saturday" - - offer him some special reward or outing to let him see firsthand the reward of his controlling himself.