Malfunctioning VTEC=oil sludge suspected?

The car had high miles and poor maintenance/sludgy oil when I bought it 2 years ago. The component that affects valve timing (VTEC) was replaced along with a few oil changes to help clean it out. (Side note. Honda dealer wanted to replace my transmission. For double what it should cost.) When the VTEC malfunctions, it feels like a shifting problem, and this fix took care of it for the past two years. But today, I have a similar problem and think it might be a similar issue. I feel like making sure the engine is clean and the valve is clear might be a good first step in figuring out why my Honda a struggling. After a half hour or so on the road, it will occasionally have trouble getting back up to speed. The shifting is rough and it feels like reduced power. I have to put flashers on and stay to the right and slowly regain speed. I'm not a mechanic, and I'd like to see if cleaning oil passages is a reasonable request or do I sound crazy. And if it's not nuts, what would be a reasonable charge. I'd like to rule out engine issues before digging into possible transmission issues.