Thanks a lot! That really helps, at least at theoretical level because I’m writing this “thank-you reply” before trying it on my development environment. 
In my case it will be pretty easy to avoid writes because only writes I have are web-form triggered, when user submits a suggestion to add a new product to the catalog. Everything else is triggered from admin interface and that would be only me. LoL
But it would be great to have some kind of API to call to do it at some higher level rather than implementing it on my own - that’s my thought for all Hibernate Search users more than for myself.
Thanks again!