Use an oral irrigator (such as Powerfloss), which is a handheld gadget that rapidly pulses a small jet of water into your mouth, to flush out the bad bacteria.
It can go deeper than a brush or floss can reach. Carry a toothbrush with you and brush after every meal, although it is not necessarily good advice to brush immediately after a meal: if you have consumed anything potentially erosive, like cola or citrus fruit, this can cause added damage to dental enamel. In this instance, brushing an hour after a meal is better.