It's true that most heathers do not tolerate a lime soil but some will.
But what many people do is create an area in their clay soil which is good for most heathers. First they improve the clay soil by incoroporating lots of organic matter. The more the better, the soil should end up crumbly rather than clayey. Doing this alone wil make the soil less acid. Then they add chemicals to make the soil slightly more acidic. These are readily available in garden centres. Lastly the feed the plants with food for lime intolerant plants.
Yes, that would work. Over time (5 years or so?) the effect of the ericaceous would lessen. So the addition of a light mulch of ericaceous compost each year should maintain the acidity of the soil. It's also a good idea to feed them with lime hating plant food occasionally. Typically this is branded as azalea and rhodedendron feed.