Hello.
Thank you for reaching out regarding your Samsung - 4.5 cu. ft. Front Load Washer with Vibration Reduction Technology+ if you can was a rug. Regarding your concern, as long as the backing of the rag is not rubber, you can use the washing machine. As rugs with rubber backing may come off and stick to inside the drum, this may result in malfunction such as a drainage error.
I suggest you check this link to your user manual for assistance. Please go to page 11.
https://downloadcenter.samsung.com/content/UM/202110/20211008114718738/WF6000T_DC68-04006H-01_EN_MES_R.pdf
Should you need more assistance, please feel free to get back to us via the following options:
1. Facebook Messenger: http://m.me/samsungsupport
2. Twitter: https://twitter.com/messages/compose?recipient_id 18768513
3. Samsung Community: https://us.community.samsung.com/t5/Samsung-Community/ct-p/us
Thank you for being a valued customer of Samsung. Have a great day.
Reference Ticket Number: 1144549619
^Camille