I think the main thing with feeding hotdog is they are SUPER salty!! And too much salt can cause serious problems for your little guy!
[Note: Lots of Yorkies ARE picky eaters....HOWEVER, picky eating CAN mean there is a health issue, such as a liver shunt. Is he otherwise healthy?? Does he have any other symptoms of a liver shunt like staring into space, circling, failure to grow at a normal rate, inability to gain weight, etc...? I suggest discussing the eating issue with your vet, and possibly asking for a Bile Acid Test (pre and post eating!) to be done...it's a simple blood test that can rule out a liver shunt! Yorkies are 38 times more likely than any other breed to have a liver shunt!!]
Barring any health issues, I suggest sticking with a canned food or a kibble, simply because they are nutritionally balanced, and unless you get your "homecooked" recipe from a veterinary nutritionist who will balance the diet, I would only home cook in an emergency situation (as in, he hasn't eaten in 2 whole day!!)
It seems like you've tried a couple of decent kibbles (except Beneful, which isn't a very good quality food)....are you opposed to feeding canned food? Most dogs LOVE canned, and all the talk about canned not being good for their teeth is totally bogus! In fact, canned is way less processed than kibble, so it's probably even better for him. Personally, I have been very opposed to canned simply because I have a super sensitive nose and cannot STAND the smell of it!! HOWEVER, I found a canned food that works for us and doesn't smell too bad. It's the Natural Balance Eatables line (I get it from Petco), which actually look like something for humans...they have visible vegetables with chunks of meat and even "dumplings"!!
My Bella can be a somewhat picky eater too, so here is what I've tried with her....feel free to try any of these options:
1) soak kibble in water for 10+ min until it starts to swell a bit and gets softer--a lot of dogs prefer a softer food, plus soaking it basically rehydrates it, which makes is smell more appetizing
2) mix a tsp or 2 of cottage cheese or mashed potatoes (sweet or white) with either dry OR soaked kibble
3) mix a tsp or 2 of canned food with either dry OR soaked kibble
4) **this is what I do now** put a tsp or 2 of canned food NEXT to dry kibble...the canned will stimulate his appetite, so if he's hungry, he'll go ahead and eat the kibble too...if not, he won't, but at least he had SOMETHING (the canned) **I do this in the morning, and at night I just do dry now! After finally getting into this routine, our feeding times go much more smoothly!**
A couple of other things....a lot of people OVER feed, and think that their Yorkie isn't eating enough. Bella (4.5 lbs) eats maybe 1/4 cup of food PER DAY!! Some days a little more, some days less. And she isn't too thin...or too thick
Also, I've found that a lot of times Bella doesn't want to eat on my schedule, she wants to eat on her schedule! So, for a dog who doesn't gobble up whatever you put down for him, it's perfectly fine IMO to free feed, meaning leave dry kibble down all day. I do suggest measuring out how much you're putting down each time, just so you know how much he's eating. If you don't have a dog that overeats, why make him eat on your schedule?? Bella generally eats the smidgeon of canned I give her in the morning plus maybe 3 or 4 kibbles, and then she doesn't eat anymore until an hour or 2 later, when she eats several more kibbles. Because I have a puppy now (Maya) I leave food down for her all day, but Bella doesn't even go near it until around 5:00 or 6:00 or sometimes 7:00 at night.
If it were me, I'd try one of the above....it's best if you can entice him to eat HIS food, and then wean back some of the enticement until you're not having to work so hard to get him to eat!! Good luck!! (And at least consider having his Bile Acids tested.)