Database query:
DELETE FROM Products.BaseProductCategoryLinkActiveVariants;
DELETE FROM Products.BaseProductCategoryLink;
DELETE FROM Products.BaseProductProductListLinkActiveVariants;
DELETE FROM Products.BaseProductProductListLink;
DELETE FROM Products.RelationshipLink;
DELETE FROM Products.RelationshipTypeEntity;
DELETE FROM Products.PriceListItem;
DELETE FROM Products.InventoryItem;
DELETE FROM Products.UnitOfMeasurementEntity;
DELETE FROM Products.ProductList;
DELETE FROM Products.CategoryChannelLink;
DELETE FROM Products.Category;
DELETE FROM Products.Assortment;
DELETE FROM Products.VariantBundleLink;
DELETE FROM Products.VariantChannelLink;
DELETE FROM Products.Variant;
DELETE FROM Products.BaseProduct;
DELETE FROM FieldFramework.FieldDefinition WHERE AreaType = 'Litium.Products.ProductArea, Litium.Abstractions';
DELETE FROM FieldFramework.FieldTemplate WHERE AreaType = 'Litium.Products.ProductArea, Litium.Abstractions';
DELETE FROM Products.DisplayTemplate;
DELETE FROM Products.InventoryToCountryLink;
DELETE FROM Products.Inventory;
DELETE FROM Products.PriceListOrganizationLink;
DELETE FROM Products.PriceListToCountryLink;
DELETE FROM Products.PriceListGroupLink;
DELETE FROM Products.PriceListWebSiteLink;
DELETE FROM Products.PriceList;
DELETE FROM Products.UrlHistory
DELETE FROM Workflows.TaskMatchLink;
DELETE FROM Workflows.TaskAssignedLink;
DELETE FROM Workflows.Task;
DELETE FROM Workflows.Workflow;
If on clearing Assortment table error appears then you need to clear AssortmentSystemId from the Market table or clear Channel and Market tables before clearing Assortment table.
Clear the related rows in Common.Setting tables in order for Accelerator fields to be recreated.
Remember to restart your site so the definitions setups get implemented in the database.