Thoughts on "EL-Cheapo" LP flattener?

I have finally come up with a really nice looking,and really cheap idea for a workable LP flattener.I have employed it just yesterday,but haven't used it yet.Will start it next week,and follow up here.I felt some of you guys might save some money(for new music) should this work as I expect. What I did was to get two 12"x12" slabs of sandstone/marble,which have a nice weight to them,but not too heavy.Also,they can be purchased locally(like a flooring tile,about half inch thick)and can be had in many colors,so you can match to room decor.
I have been thinking about this for awhile, and decided against something "hard" pressing the LP,because I feel it would damage the grooves,to an extent,and I'm not happy about splurging for a pricey flattener,from a mainstream mfgr,since this year I have spent quite a bit of money on the hobby already.
So,what I did was get some very thin cork liner(easily bought from a Home Depot type store)which has one side as an adhesive.....The adhesive side is stuck to one side of the marble slab/tile(cut to perfect 12"x12" fit).You want to do this to "both" pieces!You can even place some soft felt to the bottom of one of the plates/tiles if you want to keep it on a shelf.
Now just place an LP between both slabs,and place it in a windowsill,not directly in sunlight,but enough exposure to get slightly warm.Leave this in place for a few days(I still must experiment with "time" exposure here)and I see no reason(I hope) for this not to work.The cork will not put damaging pressure on the grooves,since there is a softness to it,but it is SO thin,that the pressure of both slabs(about half inch thick,btw)should do the trick.
Here,pay close attention to temperatures on the windowsill,and maybe it is best to be very wary of what season of the year gives best results.As sunlight can get hot.REMEMBER to keep a "shade" down and not have direct exposure to sun.We just want general warmth,over a couple of days.With this,and the weight of the slabs I pretty much feel it will work,but it is a cheap/cute effort,so worthwhile.Some of you may have better ways of getting it to be more effective,and I am all ears!
I have a good hunch this should work,but some experimentation will be necessary.In my room,it looks quite nice,as it matches my room decor,and takes up very little space.

All in all,this cost me a total of 8 dollars!
Best.