Unilever are VERY hard to boycott. They make almost the entire market of their products including a lot of "own brands".
Not really, but this depends on two things: what kinds of products you desire, and where you live.
Almost everything in the link you sent is a "novelty" or "luxury" product. I read most of that page, and personally, the items I don't buy because I don't need, or I have alternatives that are eco-conscious or local. I mean look at that list: popsicles, ice cream, bullion, pre-made salad dressing, pre-made side dishes, low-cost ice cream, pre-made sauces... almost none of that exists in my house because I like to cook, so my Unilever surface is apparently non-existant (I bet there are a few things I own because there are a lot of sub-brands, but at first blush, I'm making a subjective plea).
But for that last part, it all depends where you live. I have the luxury of grocery co-ops that are sustainable and I love to cook. My parents live in a food desert in upstate new york, with only one mammoth grocery store within 30 miles, and they hate cooking. They even hate washing dishes: they buy plastic forks and paper plates and throw it all out AFTER EVERY MEAL.
But developed cultures have trouble with "not needing novelty", and convenience seems to always win, which makes the fight all that much harder.