Set programmatically product sale price and cart item prices in Woocommerce 3

Question

This is the continuation of : Set product sale price programmatically in WooCommerce 3

The answer works, however once a user adds the product to cart, the old price stil

Answer 1

@LoicTheAztec answers works very nicely, but is not required.

You need to filter at least woocommerce_product_get_price and woocommerce_product_variation_get_price with the dynamic_sales_price_function.

To make it work really smoothly, you need some more filters as well.