My adult basenjis can wear them without any fuss.
Our dogs won't tolerate a muzzle anymore (used the soft muzzle). The vet used them to trim their nails (which they always have despised having done), It worked great in the beginning but as time went on (several years) they became aware of what the muzzle meant. Now they even see a muzzle or even bring one close to them they bare their teeth and are ready to go at it and if you can hurry up and slip on one they go crazy and somehow get out of it using their paws to pull it off their heads.
We did it all wrong. We should have trained them early to wear a muzzle and just put it on give them treats to make it positive. The problem was, when they were young they were fine with having everything done to them, but as they grew older they decided they were not going to have any part of their nails being trimmed. We never foresaw having to use a muzzle and now we are paying for it. We can do anything we want with them except the nail trimming- they drew a line in the sand on nails.
Basenji's are really smart and very impressionable, what might be fine one day can fly out the window the next or much further down the road as we have learned. They don't get fooled again.
These are very smart dogs and are much like the Chinese- they have long term goals to try to get what they want and work very slowly, towards their goals.
Leash walking is another one of their long-term goals. At first no sniffing was allowed. So when they had to go potty they sniffed around and did their business. Ah! So they learned if I pretend I have to go, I can sniff around till I go, which they do, but now after enough time to read the morning paper!
It did not start like that, oh no. They worked little by little, inch by inch over years to get their way.
Also they learned not to go potty right away on walk or we might just bring them in right away (winter). Now they wait till either they can't hold it, or just before we get home to do number 2.
These are very crafty animals, be warned. Like the Chinese they don't care how long it takes to achieve their little domination plots.
What I have learned you can never back off anything or else they will take advantage of you so fast. I can't even talk on the phone without them pestering me!
That's what crates are for!