Hi people in the boxes...I have just finished a DIY floor sanding of a three bedroom house of hardwood floors. Trouble is some of the areas now show as having some deep stains, like splash marks - no idea what they were originally - probably food in the kitchen. Plan to coat whole house with poly. Wasnt planning to stain but need ideas how to fix/disguise these old stains? Saw a thread about 'sandwiching'. Anyone know if that process may help? Thanks in advance....