AInstead of making some of your visitors feel uncomfortable by requesting them to expose their natural strongly odored beauty or artistic socks (with holes), you may suggest them to try out a simpler, cheaper and perhaps hassle-free option for most of them:
=> (since there's less chance making your visitors feel uncomfortable or havingShoe bags: plastic bags for shoes
Having a shoe rack for placing smelly used (and not so cheap) slippers may not be as convenient as you might think at first (especially for strangers who might think it's a private shoe rack) is. Having a small seat at the entrance with these plastic bags clearly visible on it will also allow more people to useunderstand your intention without the need for you to say a word plastic bags for shoes:
(a written paper might help too).
I found, used and reused these a few times when I travelled in China (people's. In a few houses or sometimes stores)I visited at first, the owners would request me to wear them and would gladly dispose of them when I left. EvenLater on, if they were not too dirty, I'd keep them myself and reuse them next time. I even reused these in a few stores making the person refusesemployees a bit happier (especially in cats and dogs rains).
This does not require you to impose on your guests as much as requiring them to take out his/hertheir shoes, you can always request him/her to use these bags off. If your goal however, is to make them realize it is preferable to walk barefoot in your house (socks on/off) and your guest is likely to refuse or forget to take his/her shoes off, you can choose a more vibrant and noticeable color (e.g. flashy pink or, white or hello-kitty-heart-shaped printed plastic?)... and point to the plastics box before they enter with a smile :)