Dog grooming for very anxious dog. Please help.

[Fushia123]

Our lovely cocker spaniel is 11 and regularly went happily to the local groomers for wash, cut etc. until about a year ago. For some reason he wouldn’t let them touch his front legs and often came home groomed but not on the legs. We can stroke his legs at home no problem. He is strong and really fights and struggles to get away when he goes to the groomers. We’ve tried other dog groomers, mild sedation and even the vet who had to eventually put him under to clip all excess hair. They told us they wouldn’t do it again as his heart rate went slower during the procedure.
We have a Belfast sink at home and we put him in there to try and contain him - one of us distracts with food whilst the other clips quickly with sharp scissors. We have ‘quiet’ clippers but we can’t get near him with them. I’ve tried to find a groomer that could come into the house to do it together but have had no luck.
We wash and dry his legs and feet after walks but are at a loss about how to proceed now. Any advice please - it’s hot and he’s walking around with a long, fluffy furry coat and boots.

Could you try that thing I’ve seen for cutting nails where you cut 5 holes in a bag for life, and hang him up?

Retired groomer of over 20 years here. If a vet had to eventually sedate him to complete his groom that tells me hes a nightmare and out of control. Is he matted?if so, This is very painful for him as to clip his fur off its a case of getting under the matts super short and close to his skin. This takes skill and surgical blade.
giving him treats whilst he’s playing up for you in the sink is rewarding his bad behaviour rather than acting as a distraction. I feel Your only hope is to desensitise him by every evening while hes calm run the clippers over him gently without switching them on. Once hes got used to accepting that switch them on but dont touch him with them once hes used to the noise and is unfazed put your hand over the blade end and stroke him with that hand. He will feel the vibration through your hand. Once hes used to that sensation and only then start clipping him. Start away from his head.
all treats are given after each of these stages not during. So you reward the good behaviour once its completed.
if he shows any aggression towards you or gives you the run around then chastise him do not allow him to control you by stopping. he has to have this done for his own health and well being. If you back off he wins you lose.
hes obviously learned that if he throws himself around or becomes aggressive he will get away with this and it will stop.
ive done this process many times before with un groomable dogs and it works. However it takes weeks of patience.
meanwhile brush him daily and take no refusal because if hes matted when you get to the clipping stage it will hurt him unless you use a surgical blade which may cut him if he moves around.
if a vet wont groom him under sedation and you dont master this then his coat will become unmanageable, hot and painful eventually restricting his movement and is a hygiene problem too.
dont bath him if hes tangled or matted as it will become far worse, More matted and felt like. Super difficult to trim
good luck. Go slow and do not back down. You’re not hurting him you’re helping him.

You are obviously very experienced and knowledgeable. Thank you so much for such comprehensive advice. I will show your reply to my DH later and we will consistently stick to it. Thank you so much - really appreciate it. X