I think it is possible. Typical web process memory size is about 30-500 Mb. Writing 500 Mb sequentially on a spinning HDD takes 5 to 10 seconds, and probably you can discard a lot before saving (like JIT code, JS bytecode, CSS dependency trees, HTTP caches, localstorage etc.), and 500 Mb pages are rare.

For comparison, if you don't unload the page completely, and system gets into swapping then there will be random access pattern with speed about 400 Kb/s on a HDD. So it is faster to unload 500 Mb sequentially than swap out/in 5 Mb.