I have read on many posts that Lidocaine or in fact any "ocaine" can be toxic to chickens even at low doses and/or applied topically.
I did the crop surgery on a pullet that I had massaged for about 10 days and like you there was a reduction in size but the vegetation that was left would not shift and I was confident she would die if I did not act. She was a bantam and she had lost so much weight and the crop contents were so heavy that it was constantly tipper her forward and she could only stay upright by resting it on the ground. I removed a baseball sized mass of soggy ravelled vegetation from her crop that would never have travelled up or down her digestive tract and had been there for at least 10 days, since I had removed her from access to anything other than a thin gruel made with water and oil and soaked pellets with a few Nutri Drops in it and incontinence pads for bedding. The sight of it vindicated doing the surgery for me. I'm sure it was not pleasant for her and she did struggle during the initial incision and unfortunately refluxed and aspirated and I thought she had died a couple of times, but as soon as I had glued her back together and let go of her she was on her feet and running around and eating scrambled egg like her life depended on it 10 mins later. She was skin and bone at that time but exactly 2 weeks after the surgery she was back up to weight and laid an egg. Sadly she had a predisposition to eat straw/hay etc and within 10 mins of being put back in the pen with the others, she had grabbed and swallowed another strand. I did my best to keep access to a minimum but had to balance it against quality of life and sadly she became impacted again and at that time other issues in my life were taking my attention and 6 months later she had impacted again. I did the surgery a second time but I had let her go too far and she was not strong enough to recover. Having done the surgery twice, I don't have any great qualms about not using anaesthetic, especially as she was so full of life after the first surgery..... you really would not believe how quickly she recovered. Even having aspirated some of the contents of her crop, she wheezed and rattled for a few days and I was sure she would die, but she came right without any medication at all. I glued the crop back together with super glue and left the outer incision open in case it needed to drain and just packed it with Germolene. I did not touch her for at least 3 days after the surgery because she was breathing so badly I did not want to stress her. I just cleaned her box and gave her food and water and talked to her and the incision healed brilliantly.
If you decide to go for the surgery, let me know as I have a few tips that I learned from my mistakes..... I'm sure your husband will make a much more professional job than I did, but it helps to learn from other peoples mistakes and find out what works and what doesn't. I didn't even have medical equipment.... just a craft knife set and some tweezers and a syringe with boiled sea salt solution to irrigate once I had removed the mass and I cleaned everything in Hibiscrub before I started.
I can say that whilst doing the surgery was terrifying for me.... I am as soft as muck so cutting into a live creature was horrific.... I felt totally vindicated by the result, both in terms of seeing what was in there and that it would never have shifted and the speed of her recovery. I am just sad that she got herself back into the same situation again and I was unable/maybe unwilling to prevent it since her quality of life would have been intolerable if I had kept her in isolation without any bedding or access to vegetation.
You can try a stool softener like Dulcolx without stimulant to see if that will help shift it. Personally I would not give grit to an impacted bird. The crop is not thick enough to take the abrasion of massaging with grit inside it like the gizzard is designed to do and that may lead to inflammation and perhaps infection or yeast overgrowth. Also, the grit will struggle to pass through the mass of tangled vegetation and so it will just add to the impaction.