Re difficulty
I think why this might be considered more difficult is because a felted vessel hollow-form is more complicated than just a simple flat piece. And the size is fairly big for wet-felting.
I don’t think it’ll be a big challenge to you though, especially if you do a small test first
Also, full size, this project will use a goodly amount of fiber. One way to mitigate costs is find a cheaper base under color you like, then put your more expensive color on the outer facing layers
MY SUGGESTION
Would be to test drive process on smaller felted vessel like a bowl size. Plus you can determine shrinkage and extrapolate logistics for larger item
(Looked at tutorial)
The instructions should work. Might be some trial and error of course, but generally they’re not bad or stupid instructions. (Love the Internet) It incorporates the prerequisites to wet felt something (heat/agitation, thermal shock of hot to cold). The clothes dryer step will shrink/tighten and firm further. Throw blue jeans and/or tennis balls in with it for further abrasion. Check frequently
The hand sander idea isn’t bad for agitation once everything prepped (or you’re there forever doing it by hand). Bubble wrap is a regular thing with most folks doing wet felting. Bigger hunks, you can get from shipping stores
Re soap
Soap, if not that olive soap they mention (I guess gentle?), the DISH SOAP they mention, you want the BLUE dawn dish soap. It’s gentle. DO NOT use orange cleaners etc. Terrible on fibers.
Cleaning raw fleece, everyone uses the blue Dawn, or Orvus (get at feed store, used to clean farm animals), or there’s special fleece soaps out there like Unicorn Scour and Dirty Rotten Bastard (love the names). The idea is gentle and won’t strip the crap out of the fiber or make it brittle. You’re not scouring to get lanolin out, but principle of being gentle on fiber still the same
I have always used the first two (blue dawn or orvus). Dawn is more convenient to acquire. A thing of Orvus is around $20-25 from feed store and cheaper per pound, but that’s if you’re doing much scouring. Dawn is good for smaller random projects.
Generally you put enough soap in until the water feels slippery. It doesn’t take much. Too much, it’s PIA to get it rinsed back out and not good to leave in (pH issue, why vinegar is in final rinse)
Re sources for roving and comments
IMPORTANT
First, AVOID anything with “superwash” in name. It won’t felt. It’s been processed specifically not to. Popular for items folks want to be machine washable
Article suggested merino, which is fine. Generally it’ll run $3ish/oz for dyed.
Natural colored fibers usually cheaper
Dyed
-you have mill-dyed and mixed
-or painted (hand-dyed) roving (see Etsy)
Other comparable breeds for fine wool felting
-BFL (blue faced leicester) —common and good substitute, very similar hand
-most breeds that are 20-25 micron should work
-if you want to look up a breed, this has been my go-to resource for years. Definitely has micron info. Some sellers vary whether they mention micron size of fiber (though a selling point for fine wool so often there)
Avoid (I scanned some offerings on sites listed below)
—churro (coarse), cheviot (coarse), babydoll southdown (down breed, bad for felting), jacob (they vary wildly), romney (varies too much), gotland (coarse), corriedale and Shetland might be ok but I’d test, Icelandic (coarse)
Sources
Etsy, lots of sellers, search merino or BFL roving and tons will come up. CAREFUL to watch for superwash though. Price will depend on if commercial reseller prep vs indie-dyed
The Woolery—they have nice natural colors. Merino or BFL, and solid dyed merino
Paradise Fibers has a little sale right now on the commercial multicolored like in tutorial (common fiber, many folks sell) —34 colors
There’s also Yarn Barn, Knitpicks, etc My phone is about to die so you’ll have to dig around there
I would personally poke around on Etsy or do that paradise fibers sale unless you want natural colors. If so then look at Woolery or Etsy
Lemme know if I need to clarify anything or you have questions