I've done the irrigations with the waterpik for the last decade or so. There's no real agreement about whether there's any advantage to the waterpik over irrigations with a nasal bulb, but I know I really like the waterpik. It seems to really get into the nasal and sinus passages and in addition to momentarily clearing out mucus, it also helps for a couple hours through the beauty of osmosis. If you wiggle through enough positions and pull the water down to your mouth and things, you can really make life feel a lot better temporarily.
The tip you need for a waterpik is called a Gossan tip. It seems that independent drug stores seem to always have these, but they turn up sometimes in walgreens and you can definitely get them online. You just need the basic waterpik.
The waterpik is under $30. I don't remember the price of the tip, but under 10 for sure. For the price, I'd say it's worth trying to see if you like it.
AFterthought: the packets of sinus mix are a ripoff. You just need NON-iodized salt. I usually use canning and pickling because it's cheap and has small particles. Some people add baking soda if they're preparing a big batch, but for germ safety, you really should mix at the time. I've always just used tap water, and I asked my ENT about that due to all the info I've seen about not using tap water in nebs and he said it's really not a big deal because it's not being vaporized into your lungs. However, to be on the safe side you could definitely boil water.
Another plus of irrigations: you can do them as often as you desire, so it can be a great pick me up!