Threading - Interact With WebBrowser Object

So I am currently using the method of combining a timer with a WebBrowser control to constantly check if some particular text has appeared in the WebBrowser control on my form. The text is dynamically generated after some arbitrary amount of time depending on the user's internet connection speed. (I'm using DOM to do this). The code to check for the HtmlElements lies within a function, which is turned called by the timer.

I find that this is kind of crappy and occasionally lags the UI interface, if not making the entire program behave sluggishly. I have been thinking of just using a simple while loop in a worker thread to take care of the issue, but I understand that new threads cannot interact with the UI thread directly (including controls); they have to call wrappers that are present within the UI thread.

So my question is, can you declare a WebBrowser control and still interact with its HTMLDocument properties if you declare it within a worker thread? I don't want the while loop to be executed within the UI thread (by using a wrapper), since that would defeat the purpose. I would also like to avoid DoEvents() as much as possible...unless that's the only way to do this thing?