Black Carbon Particals on Bottom of Product at Steel Band Oven

I have a cookie product that run on Steel Band. Currently after few days (15-20 days) i observe black carbon particals problem on bottom of product. result is i have to discard that product. as a corrective measure i have to plan band cleaning on maintenance that involves in washing of band with suitable materials. But after few days situation become same, remember i have a single cookie product that run on that line continuously all the month no changeover of other product and this product is high in shortening as well.

My question is i want to eliminate this washing step as it involves manpower that is a cost and tedious process as well. I cant change the recipe as well i  mean shortening etc.

Is anyone have better solution that i my Steel band run for 6 or more months without any cleaning or production break or without any maintenance? If some one have better solution or idea can share with me. if any one using any other good practice to clean the Steel band can share with me?