We have carried out a comparative experimental study of the dc electrical conductivity s and magnetic susceptibility χ of own-made polyaniline (PANI) pellets doped with dodecybenzenesulphonic acid (DBSA), a long molecule with surfactant properties. For all samples, we find that s at low temperatures (T) is governed by the variable-range hopping (VRH) in a homogeneously disordered three-dimensional (3D) system of coupled one-dimensional (1D) chains. Depending on the doping and the corresponding disorder level, the VRH exponents are either 1/2, 2/5, or 1/4. At higher T, in all samples, we find an exponent 1 that signifies nearest-neighbour hopping. All these exponents are predicted in a model by Fogler, Teber, and Shklovskii for the charge transport in quasi- 1D Anderson-Mott insulators, and conditions for their appearance depend on disorder and T. We identified the presence of a soft (Coulomb) gap in our samples, which signifies a long-range Coulomb interaction. Change from one exponent into another in σ(T) appears at a crossover temperature T* where there are also noticeable features in χ(T). This coupling of charge and spin is discussed in the spirit of kBT being the thermal energy which causes an enhancement of the density of delocalised (Pauli) spins at the expense of localised (Curie) spins as T rises above T*. Utilising the observed correlation between spin dynamics and electronic transport, we estimate the energy scales in the electronic structure of PANI–DBSA. Utilising a property that both PANI–DBSA and multiwall carbon nanotubes (MWCNT’s) are soluble in chloroform, we have produced bulk blends of these two materials, the achieved mass fraction of MWCNT’s being up to 40 %. This is as remarkable as the accompanying effective loss of the temperature dependence of s: it decreases by only 3 times from room temperature to 10 K, whereas this decrease for pure PANI–DBSA is by a factor of 10^6. Thus, our blends simultaneously offer a solution to the problem of applications of MWCNT’s in bulk form, as well as to that of poor conductivity of PANI–DBSA at low T. It is also possible to make thin films, both of PANI–DBSA and of the blends, on a commercial plastic substrate (FR4).