I hadn't taken my machine in either for almost 3 years until I needed it serviced due to a cracked bobbin case. I was also read the "servicing act" (like the riot act but kinder LOL) but he was surprised how clean the machine actually was. I use a vacuum every couple of projects to suck out as much as possible. But I, too, should have it serviced every year. I've had my Babylock Esante for 4 years now and it's still a wonderful and reliable machine.
And, congrats on your WLS !! I'm over 4 years out and lost 100#. Can't seem to get the last 40# off but the doctor said that might happen if I can't exercise like I need to -- fibromyalgia and arthritis make it difficult. If you need some support, please feel free to PM me anytime. One thing I will tell you that happens to all of us during the first couple of months is this -- you will ask yourself "what have I done?" This is because you can't eat like you used to (which is why you had the surgery) and your emotional bond with food has been severed. This is normal and will pass. Good Luck on the new you!!!