Try the Liqui Moly one. Has good feeback and www.wasi.lk got them with discounts as well.
https://www.wasi.lk/shop/liqui-moly-catalytic-system-cleaner/
Try the liqui moly brand, I dont think lucas is available in SL. www.wasi.lk got the entire range of liqui moly and STP brand products.
https://www.wasi.lk/shop/liqui-moly-radiator-stop-leak/