Upsetting customs officials when you first enter a foreign country is never a good idea. Yet, this is something I almost achieved last year in the South Island of New Zealand when I got pinged for packing my favourite trekking boots in a rather dirty state. Lesson learned – Never pack a pair of dirty or muddy trekking boots in your baggage without giving them a good scrub and clean before you leave home. Customs in many countries have strict quarantine procedures to protect their individual and often unique eco systems and can either confiscate or fine you accordingly for either not declaring muddy boots and/or not cleaning them before entering a foreign country. Always better to be safe and clean them before leaving home.