Oddly, I am unable to find information on this model as a Sunbeam product. Rather, an instruction book for an Oster model of that number appears in searches. https://www.manualslib.com/manual/116401/Oster-6389-33.html
The Sunbeam site does offer instructions for its coffee makers but does not designate such for this specific model. https://www.sunbeam.com/service-and-support/product-support/product-faqs/kitchen-appliances/coffee-makers/kitchen-appliances-coffee-makers-faq.html
Here is a manual for a conical burr Sunbeam: https://www.sunbeam.com.au/Root/Specifications/InstructionBooklet/EM0480_ib_1.pdf
You might try Sunbeam's customer support.
The general information about cleaning coffee makers seems to contrast with the general advice on the Sunbeam page. Sunbeam seems to use vinegar. You would think there would be no controversy about this topic. Not so. Some suggest using rice; others say this may damage blades as rice is harder than cleaning pellets. Some say use bread; others say this will gum up the works. It is likely you should use the instructions that came with the manual for the product. Since you apparently lack the manual, you might contact Sunbeam customer support; the Sunbeam page does not list manuals for its coffee makers. And I cannot find even a picture of this specific model number on the web.
Answers & Comments
Oddly, I am unable to find information on this model as a Sunbeam product. Rather, an instruction book for an Oster model of that number appears in searches.
https://www.manualslib.com/manual/116401/Oster-6389-33.html
The Sunbeam site does offer instructions for its coffee makers but does not designate such for this specific model. https://www.sunbeam.com/service-and-support/product-support/product-faqs/kitchen-appliances/coffee-makers/kitchen-appliances-coffee-makers-faq.html
Here is a manual for a conical burr Sunbeam:
https://www.sunbeam.com.au/Root/Specifications/InstructionBooklet/EM0480_ib_1.pdf
You might try Sunbeam's customer support.
The general information about cleaning coffee makers seems to contrast with the general advice on the Sunbeam page. Sunbeam seems to use vinegar. You would think there would be no controversy about this topic. Not so. Some suggest using rice; others say this may damage blades as rice is harder than cleaning pellets. Some say use bread; others say this will gum up the works. It is likely you should use the instructions that came with the manual for the product. Since you apparently lack the manual, you might contact Sunbeam customer support; the Sunbeam page does not list manuals for its coffee makers. And I cannot find even a picture of this specific model number on the web.
Good luck.