Yes, you can get an OT to do IM if you want to pay for formal IM. Or you can weave it into things you're doing yourself. Personally, I think it's way outdated to pay for formal IM at this point. You have an ipad or something that can do apps (phone, kindle, anything) so get a free metronome app, use Heathermomster's instructions, and get hoppin.
I remember some of your posts about being in Brazil and looking for stuff. I agree you should NOT change what is working just to get IM, mercy. My ds could not clap slowly to anything AT ALL. Like he'd just go into this frantic hyper-clap. He couldn't clap to music, to words, nothing. My dd was easier and despite her lack of ability to keep time at least could slow down and clap. With ds I started really basic, like asking him to clap with me *twice*. I'd put my hands on his and clap slowly. Then he'd go back to frantic hyper-clap. Eventually we worked up to clapping with letters of the alphabet as I chanted them while we touched the letters. None of this is with the metronome, just building up to it.
I'm saying this is not rocket science and that you can, yourself, clap with him and see if he can even begin to slow down and clap with anything. We built up a bit at a time (you clapped 3 A, B, C, so today let's clap with A, B, C, D). Then, when he could do that, I started looking for activities to add it to. We've been doing RAN/RAS work with colored dots, so once he had read those 4 times daily for a number of weeks I started adding in the metronome. He couldn't stay with the metronome, but I just kept doing it with him. Now he's not exactly with the metronome but he can correct if he messes up a word, pause, and get back with it. It's a work in progress, kwim? That's age 6 btw.
So now he'll clap with the metronome a bit and work on it. It's not like somebody else could have gotten there faster. Well I guess you could have, but we can't do everything, mercy. The price is right the way I'm doing it and we just keep slowly building it up. He's not anywhere NEAR being able to do Heathermomster's IM homework, where dd at age 12 could just sit down and do it. With her we did Heathermomster's instructions and then started adding in digit spans for working memory when she could do the base instructions. At that point her writing took off. That was free metronome work with an app and Heather's instructions and the $17 Cusamano workbook. I was doing it with her and we got amazing changes. We maxed out what wanted and were content.
With ds the most interesting change I've seen so far is his timing when he jumps on the running trampoline (tumbletrack) at gymnastics. His whole timing was very off and uncoordinated, and when we started getting breakthroughs with the metronome his jumping also improved. It was really basic stuff, like the ability to hop down this 30' long trampoline and looking like you could feel when you were going to land and time it right or jump and get your feet up, really basic things. And since he has been doing this 2-3 days a week since May (with me in the peanut gallery watching every session), the improvements after we started metronome work were amazing.
I say do what you can for free and see where that gets you. Or if you don't want to fiddle with it, find an OT. But at $110 an hour for OT vs. the hack home version for free, the hack home version starts to look really good... Some of the sheets I've been adding metronome to are in the Focus Moves (S'cool Moves) ebook you can get on amazon for $10.
These are the links to my RAN/RAS dot and digit page files. Dropbox is free to use after you download the software. I can't promise I'll leave them in there, so if you want the files download them now. They're pdfs.
Focus Moves: Integrated Activities for Collaboration
Auditory Sequential Memory Instructional Workbook
Calling Heathermomster or another metronome guru - The Learning ...